Protected tetrasaccharides, their process of preparation and their use in the synthesis of oligosaccharides representing segments of o-antigens from diverse shigella flexneri serotypes

Abstract

The present invention provides protected tetrasaccharides, their process of preparation and their use as common scaffold precursors in the synthesis of oligosaccharides representing segments of the O-antigens from diverse S. flexneri serotypes, comprising for example SF2a, SF3a, SF2b, SF1b, SFX and / or SFY.

Description

[0001] PROTECTED TETRASACCHARIDES, THEIR PROCESS OF PREPARATION AND THEIR USE IN THE SYNTHESIS OF OLIGOSACCHARIDES REPRESENTING

[0002] SEGMENTS OF O-ANTIGENS FROM DIVERSE SHIGELLA FLEXNERI SEROTYPES

[0003] The present invention provides protected tetrasaccharides, their process of preparation and their use as common scaffold precursors in the synthesis of oligosaccharides representing segments of the O-antigens (O-Ags) from diverse S. flexneri serotypes, comprising for example SF2a, SF3a, SFlb, SF2b, SFX and / or SFY.

[0004] Carbohydrates displayed at the surface of cells and pathogens are of great therapeutic potential. On the one hand, the human glycome is being scrutinized in detail, on the other hand increasing knowledge on microbial carbohydrates and carbohydrate binding proteins offers new openings for therapeutic and prophylactic interventions. Among a large diversity of applications, carbohydrates are actively investigated as vaccine components. In this context, synthetic carbohydrates represent an attractive alternative to carbohydrate antigens of biological origin. The licensing of QuimiHib®, over two decades ago, demonstrated feasibility. Other vaccine candidates derived from synthetic oligosaccharides are under development whether targeting infectious diseases or non-transmittable diseases such as cancer.

[0005] Owing to an increasing interest in well-defined carbohydrates, progress in synthetic methodologies to complex oligosaccharides evolve rapidly. Reports on the use of scaffolds compatible with customized modifications opening the way to a diversity of targets have emerged, especially related to the synthesis of highly diverse complex 7V-glycans. Chemo- enzymatic strategies, mostly relying on the use of glycosyltransferases at the latest stages of the synthesis, are highly attractive. These two approaches were successfully combined to deliver a library of A-glycans. Similarly, glycorandomization / glycodiversification find wide applications. Yet, drawbacks in the use of glycosyltransferases include enzyme availability, added to cost and availability of the sugar-nucleotide donors.

[0006] An alternative strategy consists in the use of “engineered transglycosidase / low-cost donor” systems adapted to the customization of non-natural acceptors for the chemo-enzymatic synthesis of carbohydrates and glycoconjugates. This strategy was explored in the context of Shigella flexneri. Using mono-, di- and tetrasaccharides, feasibility was demonstrated for nonnatural acceptors. This method provides an access to a number of targets. However, efficient site-specific modification and / or subsequent chain elongation of the products of enzymatic glycosylation would require complex enzyme engineering and / or sophisticated chemical manipulation.

[0007] Shigellosis is a major diarrheal disease. It is responsible for a large burden of disease worldwide and is a leading cause of diarrheal deaths due to bacterial infection. Shigella affects especially children under 5 years of age in low- and middle-income countries (LMICs). Besides direct mortality and morbidity, it is a direct cause of stunting in this population. Shigellosis is a general problem also causing disease among travelers, military and non-governmental organization staff deployed in endemic areas. In high-income countries, it occurs in the form of outbreaks with some communities, such as young children in daycare and people in locations with poor sanitation, being particularly affected. Of additional concern in terms of public health threat is the intercontinental spread of antimicrobial resistant strains, in particular by travelers, including multidrug resistant strains.

[0008] Disease is caused by Gram-negative bacteria of the genus Shigella. Bacteria are transmitted via the fecal-oral route, through direct person-to-person contact or indirectly upon contact with contaminated food or water. The Shigella bacillus comprises four species, or groups A-D, which are subdivided in more than 50 serotypes and subtypes. S. flexneri (group B) consists of 15 or more serotypes and subtypes, whereas S. sonnei (group D) features only 1 serotype. In combination, these two species (5. flexneri and S. sonnet) account for approximately 90% of all cases of endemic shigellosis worldwide. While the latter dominates in transitional and high-income countries, S. flexneri remains prevalent in LMICs, which makes it the most important species globally. The spread of resistance among Shigella isolates increasingly compromises antibiotic treatment and emphasizes the need for alternatives among which disease prevention through vaccination is an attractive option. Altogether, epidemiological data call for a broad serotype coverage vaccine conferring primarily protective immunity to the pediatric population in LMICs. This is a challenging issue considering the diversity of circulating strains responsible for disease.

[0009] Shigella serotypes are differentiated by their surface polysaccharide and, in particular, by the O-Ag moiety, or O-specific polysaccharide (O-SP) part, of their lipopolysaccharide (LPS). The O-Ag consists of oligomers and polymers of oligosaccharide repeating units. Naturally acquitted protective immunity against shigellosis is thought to be largely serotypespecific and Shigella O-Ags are identified as major targets of protection against reinfection. Accordingly, numerous Shigella vaccine candidates under study include an O-Ag component. Despite a diversity of vaccine candidates being designed to prevent infection by Shigella and evaluated for safety and immunogenicity in clinical trials, many of which are currently ongoing, there is yet no broadly licensed Shigella vaccine.

[0010] A major challenge resides in the need for a vaccine that is well tolerated, immunogenic and efficacious against moderate-to-severe diarrhea caused by circulating Shigella strains representative of a large diversity of serotypes, particularly among infants and children under 5 years of age in LMICs. All advanced O-Ag-based vaccine candidates, including detoxified LPS conjugates, bioconjugates, Acs-S-LPS, GMMA, MAPS, feature a glycan component of biological origin, which a priori precludes the use of well-defined O-Ag segments. As an alternative, chemically defined synthetic glycan haptens have been investigated successfully as surrogates of the natural O-Ag, especially in the case of S. dysenteriae type 1 (Proc Natl Acad Sci USA 1999, 96(9), 5194-7) and SF2a (Lancet Infect. Dis. 2021, 21, 546-58). As part of an effort to broaden S. flexneri serotype coverage, a chemo-enzymatic strategy was envisioned, whereby the type / group-specific a-D-glucosylation step is performed by use of transglucosidases acting on non-natural acceptor substrates, for example a lightly protected core disaccharide in the case of SF2a (Chem. Commun. 2015, 51, 2581) or a lightly protected tetrasaccharide scaffold (J. Org. Chem. 2021, 86, 2058-2075). Notably, the tetrasaccharide had to be carefully designed to minimize interference with enzyme recognition and activity. Therefore, masking reactive functions was limited to only three positions involved in chain elongation and functionalization post enzymatic glucosylation. To this end, the synthesis of the tetrasaccharide involved only protecting groups that could be introduced and / or cleave without affecting the remaining ones. In particular, protecting groups masking hydroxyl groups other than the anomeric position and that stoichiometrically acetylated in certain O-Ags did not demonstrate the orthogonality necessary in the present case to achieve the targeted O-Ag segment chemically on demand, in a highly efficient divergent manner. However, in the latter case the enzymatic glucosylation step proved to be demanding, necessitating the implication of state-of-the art protein modelling and engineering, and conversion rates remained low.

[0011] Accordingly, it is an object of the present invention to provide versatile core precursors, namely, specifically protected tetrasaccharide scaffolds, able to provide access to a large diversity of S. flexneri O-Ag segments in a highly efficient divergent manner. Indeed, key repeating units (RU) building blocks featuring serotype-specific substitutions and functionalized to enable subsequent chain extension were built from such a single orthogonally protected scaffold. Another aim of the present invention is to provide a way to a large variety of selected targets in the context of vaccine development against shigellosis. In particular, the present invention relates to a chemically synthesized specifically protected tetrasaccharide designed as a common scaffold precursor to conjugates comprising oligosaccharides representing segments of the O-Ags from diverse S. flexneri serotypes, for example SF2a, SF3a, SFlb, SF2b, SFX and / or SFY.

[0012] Thus, in one aspect, the present invention relates to a tetrasaccharide compound of following formula (O): wherein:

[0013] R is (9-allyl (O-All), (9-triisopropylsilyl (O-TIPS), (9-terZ-butyldiphenylsilyl (O-TBDPS), O- tert-butyldimethylsilyl (O-TBS or (9-TBDMS), (9-thexyldimethylsilyl (O-TDS), O-para- methoxyphenyl (O-PMP) or SRo, with Ro being such as the compound is a thioglycoside, said Ro being for example phenyl, tolyl, ethyl, CH2-( / c / 7-butyl-Ph) or 2-tert-butyl-5-methylphenyl; R’ is NHC(O)CC13, NHC(O)CHC12, NAC2, NHTroc with Troc being 2,2,2- trichloroethoxycarbonyl, a carbamate such as NHCbz, with Cbz being carboxybenzyl, NAlloc, with Alloc being allyloxycarbonyl, NHC(O)CF3, tetrachlorophtalimido, phtalimido, or azido;

[0014] Ri is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac), and R2is levulinoyl (Lev), fluorenylmethoxycarbonyl (Fmoc), or pentafluorophenyl ester (PFP); or R2is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac), and Ri is levulinoyl (Lev), fluorenylmethoxycarbonyl (Fmoc), or pentafluorophenyl ester (PFP);

[0015] R4, Rs and Re are independently chosen from arylmethyl protecting groups, in particular benzyl (Bn), / % / ra-chlorobenzyl (PCB), / % / ra-bromobenzyl (PBB), / % / ra-nitrobenzyl or ortho- nitrobenzyl;

[0016] R3, R7 and R8 / R9 are protecting groups that are orthogonal to each other and orthogonal to R, Ri, R2, R4, Rs, Re and R’. Alternatively, R2is a protecting group that is orthogonal to R, Ri, R2, R3, R4, Rs, Re, R7, R8 / R9 and R’, and capable of assistance, in particular anchimeric assistance and / or by steric hindrance.

[0017] In particular, R’ is NHC(O)CC13, NHC(O)CHC12, NAc2, NHTroc, tetrachlorophtalimido, or azido, more particularly NHC(0)CC13.

[0018] In particular, R is O-allyl (O-All), and / or R’ is NHC(0)CC13.

[0019] In another aspect, the present invention relates to a tetrasaccharide compound of following formula (O’):

[0020] (O’), wherein:

[0021] R is O-allyl (O-All), O-triisopropylsilyl (O-TIPS), O- / c / 7-butyldiphenylsilyl (O-TBDPS), O- / c / V-butyldimethyl silyl (O-TBS or O-TBDMS), O-thexyldimethylsilyl (O-TDS), O-para- methoxyphenyl (O-PMP) or SRo, with Ro being such as the compound is a thioglycoside, said Ro being for example phenyl, tolyl, ethyl, CH2-( / c77-butyl-Ph) or 2-tert-butyl-5-methylphenyl; Ri is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac), and R2is levulinoyl (Lev), fluorenylmethoxycarbonyl (Fmoc), or pentafluorophenyl ester (PFP); or R2is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac), and Ri is levulinoyl (Lev), fluorenylmethoxycarbonyl (Fmoc), or pentafluorophenyl ester (PFP);

[0022] R4, Rs and Re are independently chosen from arylmethyl protecting groups, in particular benzyl (Bn), / % / ra-chlorobenzyl (PCB), / % / ra-bromobenzyl (PBB), / % / ra-nitrobenzyl or ortho- nitrobenzyl;

[0023] R3, R7 and R8 / R9 are protecting groups that are orthogonal to each other and orthogonal to R, Ri, R2, R4, RS, Re and NHC(O)CC13.

[0024] Alternatively, R3, R7 and Rs are protecting groups that are orthogonal to each other and orthogonal to R, Ri, R2, R4, Rs, Re and NHC(O)CCh, and R9 is Bn. Orthogonality and orthogonal protecting groups in carbohydrate chemistry are well known from the skilled in the art, and are in particular described in Agoston etal. (Tetrahedron: Asymmetry 27 (2016) 707-728).

[0025] Thioglycosides are well known from the skilled in the art. Reference is made for example to Advances in Carbohydrate Chemistry and Biochemistry, Volume 52, 1997, Pages 179-205 and Carbohydr. Res. 2015, 403, 13-22.

[0026] In a particular embodiment, Ro is chosen from:

[0027] Ci-Cn-alkyl, in particular Me or Et;

[0028] Ci-Cn-alkyl-Ar, wherein Ar is an aryl, optionally substituted, notably by one or more groups chosen from Ci-Ce alkyl, O-Ci-Ce alkyl, NO2, in particular (CH2)3-Ph, CH2-(tert-butyl-Ph) (MBP),

[0029] Ci-Cn-alkyl-Het, wherein Het is a heteroaryl, optionally substituted, notably by one or more groups chosen from Ci-Ce alkyl, O-Ci-Ce alkyl, NO2, Ci-Ci2-alkenyl, in particular Me or Et;

[0030] Ci-Cn-alkenyl-Ar, wherein Ar is an aryl, optionally substituted, notably by one or more groups chosen from Ci-Ce alkyl, O-Ci-Ce alkyl, NO2, in particular (para- methoxyphenyl)-4-pentenyl (MPTG),

[0031] Ci-Cn-alkenyl-Het, wherein Het is a heteroaryl, optionally substituted, notably by one or more groups chosen from Ci-Ce alkyl, O-Ci-Ce alkyl, NO2, aryl, optionally substituted, notably by one or more groups chosen from Ci-Ce alkyl, O-Ci-Ce alkyl, NO2, in particular phenyl, tolyl, Ph-NCE, 2- / c / 7-butyl-5- methylphenyl; heteroaryl, optionally substituted, notably by one or more groups chosen from Ci- Ce alkyl, O-Ci-Ce alkyl, NO2, in particular pyridyl, indolyl, benzoxazolyl (Box); and or is such as SRo is an alkoxythioimidate;

[0032] Ro being more particularly phenyl, tolyl, ethyl, CH2-( / c77-butyl-Ph) or 2- / c77-butyl-5- methylphenyl.

[0033] In a particular embodiment, the invention also concerns a tetrasaccharide compound of following formula (Io):

[0034]

[0035] (Io), wherein:

[0036] R is O-allyl (O-All), O-triisopropylsilyl (O-TIPS), O-tert-butyldiphenylsilyl (O-TBDPS), O- tert-butyldimethyl silyl (O-TBS or O-TBDMS), O-thexyldimethylsilyl (O-TDS), O-para- methoxyphenyl (O-PMP) or SRo, with Ro being such as the compound is a thioglycoside, said Ro being for example phenyl, tolyl, ethyl, CH2-( / crt-butyl-Ph) or 2-tert-butyl-5-methylphenyl; Ri is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac), and R2 is levulinoyl (Lev), fluorenylmethoxycarbonyl (Fmoc), or pentafluorophenyl ester (PFP); or R2 is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac), and Ri is levulinoyl (Lev), fluorenylmethoxycarbonyl (Fmoc), or pentafluorophenyl ester (PFP);

[0037] R3 is tert-butyl dimethyl silyl (TBS), triethylsilyl (TES), triisopropyl silyl (TIPS), 2- methylnaphthyl (Nap), / % / ra-methoxybenzyl (PMB), / % / ra-bromobenzyl (PBB), para- chlorobenzyl (PCB), / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, 2-pyridylmethyl (picolinyl), picoloyl ester (pico), or allyl (All);

[0038] R4, Rs and Re are independently chosen from arylmethyl protecting groups, in particular benzyl (Bn), / % / ra-chlorobenzyl (PCB), / % / ra-bromobenzyl (PBB), / % / ra-nitrobenzyl or ortho- nitrobenzyl;

[0039] R7 is 2-methylnaphthyl (Nap), para-m ethoxybenzyl (PMB), / % / ra-bromobenzyl (PBB), para- chlorobenzyl (PCB), tert-butyldimethylsilyl (TBS), tri ethylsilyl (TES), triisopropyl silyl (TIPS), / % / ra-nitrobenzyl, ortAo-nitrobenzyl, 2-pyridylmethyl (picolinyl), picoloyl ester (pico), allyloxycarbonyl (Alloc) or allyl (All); none or only one of R, OR3 and OR7 being OA11;

[0040] R7 being different from PBB and PCB when at least one of R4, Rs and Re is PBB or PCB; with R3 being TBS or TES, and R being different from TIPS, TBDPS, TBS and TDS, when R7 is Nap, PMB or PBB, with R3 being Nap, PMB or PBB, and R being different from TIPS, TBDPS, TBS and TDS, when R7 is TBS or TES; with R3 being Nap and R7 being PMB or PBB, or R7 being Nap and R3 being PMB or PBB, when R is TIPS, TBDPS, TBS or TDS, with R3 being TBS, TES, TIPS, PMB, PCB, PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R7 is Nap, and R3 being Nap, PMB, PCB or PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R7 is TBS, TES, or TIPS; and with R7 being TBS, TES, TIPS, PMB, PCB, PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R3 is Nap, and R7 being Nap, PMB, PCB or PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R3 is TBS, TES, or TIPS;

[0041] Rs and R9 form together a benzylidene acetal (Bzl), cyclohexylidene acetal or isopropylidene acetal, or, when R3 and R7 are not Nap, / % / ra-nitrobenzylidene acetal or naphthylidene acetal, or silylidene (DTBS), when none of R3 and R7 is TBS, TES, or TIPS, in particular TBS.

[0042] In a particular embodiment, Ri is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac), and R2 is levulinoyl (Lev), fluorenylmethoxycarbonyl (Fmoc), or pentafluorophenyl ester (PFP).

[0043] In a particular embodiment, R2 is levulinoyl (Lev).

[0044] In a particular embodiment, Ri is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac), and R2 is levulinoyl (Lev).

[0045] In a particular embodiment, R4, Rs and Re are Bn.

[0046] In a particular embodiment, R4, Rs and Re are / % / ra-chlorobenzyl (PCB), para- bromobenzyl (PBB), / % / ra-nitrobenzyl or ortAo-nitrobenzyl, and R3 and R7 are not PCB, PBB, / % / ra-nitrobenzyl, or ort / zo-nitrobenzyl.

[0047] In a particular embodiment, R4, Rs and Re are identical.

[0048] In a particular embodiment, the invention also concerns a tetrasaccharide compound of following formula (I):

[0049] wherein:

[0050] All is allyl;

[0051] Ri is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac);

[0052] R2 is levulinoyl (Lev) or fluorenylmethoxycarbonyl (Fmoc) or pentafluorophenyl ester (PFP), in particular Lev or Fmoc, even more particularly Lev;

[0053] R3 is / c / V-butyldimethylsilyl (TBS), triethylsilyl (TES), 2-methylnaphthyl (Nap), para- methoxyphenyl (PMB) or / % / ra-bromobenzyl (PBB);

[0054] R4, Rs and Re are independently chosen from arylmethyl protecting groups, in particular benzyl (Bn), / % / ra-chlorobenzyl (PCB), / % / ra-bromobenzyl (PBB), / % / ra-nitrobenzyl or ortho- nitrobenzyl;

[0055] R7 is 2-methylnaphthyl (Nap), / % / ra-methoxyphenyl (PMB), / % / ra-bromobenzyl (PBB), tert- butyldimethyl silyl (TBS) or tri ethylsilyl (TES);

[0056] R7 being different from PBB and PCB when at least one of R4, Rs and Re is PBB or PCB; with R3 being TBS or TES, and R being different from TIPS, TBDPS, TBS and TDS, when R7 is Nap, PMB or PBB, with R3 being Nap, PMB or PBB when R7 is TBS or TES, and R being different from TIPS, TBDPS, TBS and TDS; with R3 being Nap and R7 being PMB or PBB, or R7 being Nap and R3 being PMB or PBB, when R is TIPS, TBDPS, TBS or TDS, with R3 being TBS, TES, TIPS, PMB, PCB, PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R7 is Nap, and R3 being Nap, PMB, PCB or PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R7 is TBS, TES, or TIPS; and with R7 being TBS, TES, TIPS, PMB, PCB, PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R3 is Nap, and R7 being Nap, PMB, PCB or PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R3 is TBS, TES, or TIPS; Rs and R9 form together a benzylidene acetal (Bzl), cyclohexylidene acetal or isopropylidene acetal, or, when R3 and R7 are not Nap, / % / ra-nitrobenzylidene acetal or naphthylidene acetal, or silylidene (DTBS), when none of R3 and R7 is TBS, TES, or TIPS, in particular TBS.

[0057] In a particular embodiment, the invention also concerns a compound as defined above, of following formula (Ii):

[0058] (Ii), wherein:

[0059] All is allyl;

[0060] CA is chloroacetyl;

[0061] Lev is levulinoyl;

[0062] TBS is / c / V-butyldimethylsilyl;

[0063] Bn is benzyl;

[0064] Nap is 2-methylnaphthyl.

[0065] In another aspect, the invention also concerns a process of preparation of a compound as defined above, comprising a step of contacting a donor of formula (IA) with an acceptor of formula (IB) to yield said compound of formula (I), said formula (IA) being as follows: wherein: G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA) or trichloroacetimidyl (TCA);

[0066] R1-R7 being as defined above; said formula (IB) being as follows:

[0067] (IB),

[0068] R8-R9 being as defined above.

[0069] R is in particular chosen from thioimidates, for example S-benzoxazolyl (SBox), S- benzimidazolyl (SBiz), 5-thiazolinyl (STaz), 3,3-difluoro-3H-indol-2-ylthio (SFox), alkoxythioimidates, or from thioglycosides, phosphates, fluorine, alkynyl benzoates.

[0070] R is for example described by:

[0071] B. Yu and J. Sun (Chem. Commun., 2010, 46, 4668-4679),

[0072] Schmidt and al. (Adv. Carbohydr . Chem. Biochem. 1994, 50, 21; ox Angew. Chem., Ini. Ed. Engl. 1986, 25, 212),

[0073] - Org. Biomol. Chem., 2024, 22, 5214-5223,

[0074] Carbohydr. Res., 2015, 403, 115-122,

[0075] - Acc. Chem. Res. 2018, 51, 2, 507-516.

[0076] G may also represent H, the corresponding compound being in this case a hemiacetal. This hemiacetal can be activated into a donor, for example an imidate donor (anomeric OPTFA or OTCA substitution) (J. Org. Chem. 2015, 80, 11237-57), or into an alkynyl benzoate donor (Acc. Chem. Res. 2018, 51, 507-516), or into a diphenyl oxosulfonium intermediate (J. Am. Chem. Soc. 2000, 122, 4269-4279).

[0077] In another aspect, the invention also concerns a penta- or hexasaccharide compound of following formula (II):

[0078] wherein: one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; the other R1-R7 groups are as defined above; when Rs represents a protected residue a-D-Glcp-, R’9 is a protecting group to which All, R2, R3 and R7 are orthogonal; and when Rs does not represent a protected residue a-D-Glcp-, Rs and R’9 form together a benzylidene acetal (Bzl) or isopropylidene acetal. Alternatively, R’9 is in particular a protecting group that is orthogonal to R2, R3 and R7.

[0079] More particularly, when Rs represents a protected residue a-D-Glcp-, R’9 is a protecting group that is orthogonal to R2, R3 and R7.

[0080] In another aspect, the invention also concerns a penta- or hexasaccharide compound of following formula (II):

[0081] wherein: one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; or Rs represents a-D-Glc / ?-(l— >2)-a-D-Glcp; the other R1-R7 groups are as defined above; when Rs represents a protected residue a-D-Glcp- or a-D-Glcp-(l— >2)-a-D-Glcp, R’9 is a protecting group to which All, R2, R3 and R7 are orthogonal; and when Rs does not represent a protected residue a-D-Glcp- or a-D-Glc / ?-(l— >2)-a-D-Glc / ?, Rs and R’9 form together a benzylidene acetal (Bzl) or isopropylidene acetal.

[0082] In particular, one of Rs, R7 and R3 represents a protected residue a-D-Glcp-. The compound of formula (II) is in this case a pentasaccharide.

[0083] In particular, when Rs represents a protected residue a-D-Glcp-, R’9 is a primary hydroxyl protecting group, in particular a protecting group which is selective for primary hydroxyl group.

[0084] In particular, when Rs represents a protected residue a-D-Glcp-, R’9 is chosen from arylmethyl protecting groups, in particular Bn, PCB, PBB, PMB, / % / ra-nitrobenzyl or ortho- nitrobenzyl, Nap, hindered esters, Ac, and, when R3 is not TBS or TES, TBDPS, TES, TBS and thexyl (TDS), notably TBDPS and TES.

[0085] In particular, Rs represents a-D-Glcp-(l— >2)-a-D-Glcp. Alternatively, one of R7 and R3 represents a protected residue a-D-Glcp-, Rs represents an arylmethyl protecting group, in particular Bn, PCB, PBB, PMB, / % / ra-nitrobenzyl or ortho- nitrobenzyl, and R’9 is chosen from Nap, hindered esters, and Ac.

[0086] Alternatively, one of R7 and R3 represents a protected residue a-D-Glcp-, Rs represents Bn, and R’9 is chosen from PCB, PBB, PMB, / % / ra-nitrobenzyl or ort / zo-nitrobenzyl, Nap, hindered esters, and Ac.

[0087] In particular, two of Rs, R7 and R3 represent a protected residue a-D-Glcp-.

[0088] More particularly, R7 and R3 represent a protected residue a-D-Glcp- The compound of formula (II) is in this case a hexasaccharide.

[0089] In another aspect, the invention also concerns a pentasaccharide compound of following formula (II): wherein:

[0090] Rs, R7 or R3 represents a protected residue a-D-Glcp-; the other R1-R7 groups are as defined above; when Rs represents a protected residue a-D-Glcp-, R’9 is chosen from Bn, Nap, PMB, PBB, and, when R3 is not TBS or TES, TBDPS, TES, TBS and thexyl (TDS), notably TBDPS and TES, and when Rs does not represent a protected residue a-D-Glcp-, Rs and R9 form together a benzylidene acetal (Bzl), cyclohexylidene acetal or isopropylidene acetal, or, when R3 and R7 are not Nap, / % / ra-nitrobenzylidene acetal or naphthylidene acetal, or silylidene (DTBS), when none of R3 and R7 is TBS, TES, or TIPS, in particular TBS. By “protected residue a-D-Glcp-“ is in particular meant a residue of the following formula: wherein Pi, P2, P3 and P4 are independently chosen from arylmethyl protecting groups, in particular Bn, PCB, PBB, PMB, / % / ra-nitrobenzyl or ort / zo-nitrobenzyl, and Nap. In particular, Pi, P2, P3 and P4 are identical, and are more particularly Bn.

[0091] In a particular embodiment, the invention also concerns a penta- or hexasaccharide compound as defined above, of following formula: ),

[0092]

[0093]

[0094] wherein:

[0095] Pi, P2, P3 and P4 are independently chosen from arylmethyl protecting groups, in particular Bn, PCB, PBB, PMB, / % / ra-nitrobenzyl or ort / zo-nitrobenzyl, and Nap,

[0096] R1-R9 and R’9 being as defined above, and, for SFlb’, wherein R3 may also represent Bn.

[0097] In another aspect, the invention also concerns a process of preparation of a pentasaccharide SFlb’-OAll, wherein:

[0098] , D is 3)-a-i)-GlcpNAc-( l ^ or 3)-P-D-GlcpNAc-(l^- , E represents a residue a-D-Glcp-; SFlb being in particular (9-acetylated in position 2c; and

[0099] ’ denotes that the pentasaccharide is protected as defined below, said process comprising the following steps: (i) A step of deprotection of the Rs group of a compound of formula (I), in particular by deprotecting both Rs and R9 using for example SnCh, camphorsulfonic acid (CSA) or trifluoroacetic acid (TFA), and then by protecting the obtained compound with a R’9 group using for example RVBr and Taylor reagent, RVBr with Bu2SnO activation, R’9-TCA or R’9-PTFA, R’9 being as defined above, to obtain an acceptor compound of following formula: wherein R1-R7 and R’9 are as defined above; and wherein R3 may also represent Bn;

[0100] (ii) A step of reacting the acceptor obtain in step (i) with the donor compound E-OG of following formula: wherein:

[0101] Pi, P2, P3 and P4 are as defined above,

[0102] G is an activating group, in particular Vphenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), in particular in presence of an additive, for example dimethylformamide (DMF), to yield the pentasaccharide SFlb’-OAll of following formula:

[0103] wherein R1-R7 and R’9, Pi, P2, P3 and P4 are as defined above, and wherein R3 may also represent Bn.

[0104] Such additives are for examples described in Angew. Chem. Int. Ed. 2011, 50, 7315 — 7320.

[0105] In another aspect, the invention also concerns a process of preparation of a pentasaccharide SF2a’-OAll, wherein:

[0106] , D is 3)-a-D-GlcpNAc-(l^- or 3)-P-D-G1C / ?NAC-(1^- , E represents a residue a-D-Glcp- ; and ’ denotes that the pentasaccharide is protected as defined below, said process comprising the following steps:

[0107] (i) A step of deprotection of the R7 group of a compound of formula (I), for example using 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (DDQ) and optionally P-pinene when R7 is Nap, to obtain an acceptor compound of following formula: wherein Ri-Re and R8-R9 are as defined above;

[0108] (ii) A step of reacting the acceptor obtain in step (i) with the donor compound E-OG of following formula: wherein:

[0109] Pi, P2, P3 and P4 are as defined above,

[0110] G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), in particular in presence of an additive, for example dimethylformamide (DMF), to yield the pentasaccharide SF2a’-OAll of following formula: wherein Ri-Re, R.8-R9, Pi, P2, P3 and P4 are as defined above.

[0111] In another aspect, the invention also concerns a process of preparation of a hexasaccharide SF2b’-OAll, wherein:

[0112] SF2b is (E)AB(E)CD, with A is 2)-a-l.-Rha / i-(H’- , B is 2)-a-l.-Rha / i-(H’- , C is 3)-a-L-Rha / >- (1— > , D is 3)-a-D-GlcpNAc-(l or 3)-P-D-GlcpNAc-(l , E represents a residue a-i)-Glcp- ; and

[0113] ’ denotes that the hexasaccharide is protected as defined below, said process comprising the following steps: (i) A step of deprotection of the R7 group of a compound of formula (I), for example using 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (DDQ) and optionally P-pinene when R7 is Nap, to obtain an acceptor compound of following formula: wherein Ri-Re and R8-R9 are as defined above;

[0114] (ii) A step of reacting the acceptor obtain in step (i) with the donor compound E-OG of following formula: wherein: Pi, P2, P3 and P4 are as defined above,

[0115] G is an activating group, in particular N-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), in particular in presence of an additive, for example dimethylformamide (DMF),

[0116] (iii) A step of deprotection of the R3 group of the compound obtained in step (ii), for example using tri ethylamine trihydrofluoride (TEA.3HF) when R3 is TBS, to obtain an acceptor compound of following formula:

[0117] wherein R1-R2, and R4-R9 are as defined above;

[0118] (iv) A step of reacting the acceptor obtain in step (i) with the donor compound E-OG of following formula: wherein:

[0119] Pi, P2, P3 and P4 are as defined above,

[0120] G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), in particular in presence of an additive, for example dimethylformamide (DMF), or (i) A step of deprotection of the R3 group of a compound of formula (I), for example using triethylamine trihydrofluoride (TEA.3HF) when R3 is TBS, to obtain an acceptor compound of following formula:

[0121] wherein R1-R2, and R4-R9 are as defined above;

[0122] (ii) A step of reacting the acceptor obtain in step (i) with the donor compound E-OG of following formula: wherein:

[0123] Pi, P2, P3 and P4 are as defined above,

[0124] G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), in particular in presence of an additive, for example dimethylformamide (DMF),

[0125] (iii) A step of deprotection of the R7 group of a compound obtained in step (ii), for example using 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (DDQ) and optionally P-pinene when R7 is Nap, to obtain an acceptor compound of following formula:

[0126] wherein R1-R2, R4-R6 and R8-R9 are as defined above; (iv) A step of reacting the acceptor obtain in step (i) with the donor compound E-OG of following formula: wherein:

[0127] Pi, P2, P3 and P4 are as defined above,

[0128] G is an activating group, in particular / f-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), in particular in presence of an additive, for example dimethylformamide (DMF), to yield the hexasaccharide SF2b’-OAll of following formula:

[0129] wherein R1-R2, R4-R6, R8-R9, Pi, P2, P3 and P4 are as defined above.

[0130] In another aspect, the invention also concerns a process of preparation of a pentasaccharide SF3a’-OAll, wherein:

[0131] , D is 3)-a-D-GlcpNAc-(l^- or 3)-P-D-G1C / ?NAC-(1^- , E represents a residue a-D-Glcp-;

[0132] SF3a being in particular O-acetylated in position 2c, while the corresponding version non O- acetylated in position 2c corresponding to SFX; and ’ denotes that the pentasaccharide is protected as defined below, said process comprising the following steps:

[0133] (iii) A step of deprotection of the R3 group of a compound of formula (I), for example using triethylamine trihydrofluoride (TEA.3HF) when R3 is TBS, to obtain an acceptor compound of following formula:

[0134] wherein R1-R2, and R4-R9 are as defined above;

[0135] (iv) A step of reacting the acceptor obtain in step (i) with the donor compound E-OG of following formula: wherein:

[0136] Pi, P2, P3 and P4 are as defined above,

[0137] G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), in particular in presence of an additive, for example dimethylformamide (DMF), to yield the pentasaccharide SF3a’-OAll of following formula:

[0138] wherein R1-R2, R4-R9, Pi, P2, P3 and P4 are as defined above.

[0139] In another aspect, the invention also concerns a penta- or hexasaccharide acceptor compound of following formula (IIIA): (IIIA), wherein: one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-;

[0140] Rs, R7 or R3 representing in particular a protected residue a-D-Glcp-; the other Ri, R3-R8 and R’9 being as defined above. In a particular embodiment, the invention also concerns a penta- or hexasaccharide acceptor compound as defined above, of following formula:

[0141]

[0142]

[0143] wherein Ri, R2-R9 and R’9, Pi, P2, P3 and P4 are as defined above, and, for SFlb’, wherein R3 may also represent Bn. In another aspect, the invention also concerns a process of preparation of a penta- or hexasaccharide acceptor compound of formula (IIIA) as defined above, comprising a step of deprotection of group R2 of a compound of formula (II), in particular using hydrazine acetate or hydrazine in a mixture pyridine / acetic acid, in particular in a 1 : 1 (v / v) pyridine / acetic acid mixture when R2 is Lev. In another aspect, the invention also concerns a penta- or hexasaccharide compound of following formula (IIIDHF):

[0144] wherein:

[0145] Q is H, G or LZ, G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA),

[0146] L, which is optionally protected is: a single bond, a divalent C1-C12 alkyl chain optionally interrupted by one or more heteroatoms, notably selected from an oxygen atom, a sulphur atom or a nitrogen atom, said nitrogen and sulphur atoms being optionally oxidized, and the nitrogen atom being optionally involved in an acetamide bond, or a divalent C1-C12 alkyl chain substituted by at least one -OH group, being in particular of the following formula -(CH2-CH2-C(OH))q-(CH2-CH2)i, wherein i is 0 or 1 and q ranges from 1 to 10,

[0147] Z is a terminal function or group, optionally protected, able to form a covalent bond with a compound enabling to extend said LZ chain, a carrier and / or a solid support, or a multivalent scaffold; an anchor; a mono-, oligo- or polysaccharide; or a dye or fluorescent residue.

[0148] The protection of Z, if any, may be adapted to the R’, and Ri-R’9 groups as defined above. In particular, Z is N3, NHCbz, or NBnCbz group, in particular when R’ is NHC(0)CC13, or a protected ester, for example COOBn.

[0149] In particular, LZ is -(CH2)P-N3, -(CH2)P-NHCbz, or -(CH2)P-NBnCbz or or -(CH2)P-C00Bn, wherein p ranges from 1 to 10, in particular from 2 to 8, more particularly 2, 3, 4, 5 or 6. one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; in particular Rs, R7 or R3 representing a protected residue a-D-Glcp-; the other Ri-Rs groups are as defined above;

[0150] R’9 is as defined above.

[0151] In a particular embodiment, the invention also concerns a penta- or hexasaccharide compound as defined above, of following formula:

[0152]

[0153] wherein R1-R9 and R’9, Pi, P2, P3, P4 and Q are as defined above, and, for SFlb’, wherein R3 may also represent Bn.

[0154] In another aspect, the invention also concerns a pentaor hexasaccharide donor compound of following formula (IIID):

[0155] (IIID), wherein: G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; in particular Rs, R7 or R3 representing a protected residue a-D-Glcp-; the other Ri-Rs and R’9 groups are as defined above.

[0156] In a particular embodiment, the invention also concerns a penta- or hexasaccharide donor compound as defined above, of following formula:

[0157]

[0158]

[0159] wherein R1-R9 and R’9, Pi, P2, P3, P4 and G are as defined above, and, for SFlb’, wherein R3 may also represent Bn. In another aspect, the invention also concerns a process of preparation of a penta- or hexasaccharide donor compound of formula (IIID) as defined above, comprising a first step of deprotection of the All group, in particular using PdCh and then A-iodosuccinimide (NIS), or using hydrogen-activated (bis(methyldiphenylphosphine)) 1,5-cyclooctadiene) iridium (I) hexafluorophosphate in place of PdCh, to obtain a compound of formula (IIIH), and a second step of contacting the obtained compound with a compound of type G-LG wherein G is as defined above, and LG is a leaving group, for example PTFA-C1 when G is PTFA.

[0160] In another aspect, the invention also concerns a penta- or hexasaccharide compound of following formula (IIIH):

[0161]

[0162] (IIIH), wherein: one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; Rs, R7 or R3 representing in particular a protected residue a-D-Glcp-; the other Ri-Rs and R’9 groups are as defined above.

[0163] In a particular embodiment, the invention also concerns a penta- or hexasaccharide compound as defined above, of following formula:

[0164]

[0165] wherein R1-R9 and R’9, Pi, P2, P3, and P4 are as defined above, and, for SFlb’, wherein R3 may also represent Bn. In another aspect, the invention also concerns a functionalized penta- or hexasaccharide compound of following formula (IIIF) : (IIIF), wherein:

[0166] L and Z are as defined above; one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; in particular Rs, R7 or R3 representing a protected residue a-D-Glcp- ; the other Ri-Rs and R’9 groups are as defined above.

[0167] In a particular embodiment, the invention also concerns a functionalized penta- or hexasaccharide as defined above, wherein Z is Hal, biotin, C2-C6 alkenyl, C2-C6 alkynyl, azido, alkoxy, epoxyde, acetal, C(O)H, SRi, S(O)2-RI, NHCbz, or NBnCbz, or COOBn,

[0168] Ri being H, C(O)CHs or SR2, and

[0169] R2 being a Ci-Ce alkyl, a Ce-Cio aryl, or a 5 to 7 membered heteroaryl, such as pyridyl, or any group allowing to convert SSR2 into SH.

[0170] In a particular embodiment, the invention also concerns a functionalized compound as defined above, of following formula:

[0171] wherein R1-R9 and R’9, Pi, P2, P3, P4, L and Z are as defined above, and, for SFlb’, wherein R3 may also represent Bn. In another aspect, the invention also concerns a process of preparation of a functionalized penta- or hexasaccharide compound of following formula (IIIF), comprising a step of contacting a penta- or hexasaccharide donor compound of formula (IIID), wherein G is in particular PTFA or TCA, with a compound of formula HO-LZ’, wherein Z’ is Z, optionally protected, or a group enabling to form Z, in particular in presence of TMSOTf, TfOH, TBSOTf, AgOTf, Tf2O, Bi(OTf)3, Yb(OTf)3, B / EtsSiH, TMSB(C6Fs)4, acid-washed molecular sieves, ZnBr2, or BF3-EBO, notably in catalytical conditions.

[0172] In another aspect, the invention also concerns a functionalized penta- or hexasaccharide acceptor compound of following formula (IIIAF):

[0173] (IIIAF), wherein one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; in particular Rs, R7 or R3 representing a protected residue a-D-Glcp-; the other Ri-Rs and R’9 groups, L and Z are as defined above. In a particular embodiment, the invention also concerns a functionalized penta- or hexasaccharide acceptor compound as defined above, of following formula:

[0174] wherein Ri, R3-R9 and R’9, Pi, P2, P3, P4, L and Z are as defined above, and, for SFlb’, wherein R3 may also represent Bn. In another aspect, the invention also concerns a process of preparation of a functionalized penta- or hexasaccharide acceptor compound of following formula (IIIAF), comprising a step of deprotection of the group R2 of a compound of formula (IIIF), in particular using hydrazine acetate or hydrazine in a mixture pyridine / acetic acid, in particular in a 1 : 1 (v / v) pyridine / acetic acid mixture when R2 is Lev. In another aspect, the invention also concerns a polysaccharide compound of formula

[0175] R2-P’-OQ’, wherein P’ is constituted of or comprises at least two units, and in particular at most nine or ten units, chosen from -SFlb’-, -SF2a’-, -SF2b’- and / or -SF3a’- of following formulae:

[0176] being in particular Ac, more particularly with P’ being constituted of or comprising at least two units chosen from -SFlb’-, -SF2a’-, and -SF3a’-, at least two of these units being different,

[0177] SF2b’-,

[0178]

[0179] SF3a’-, Ri being in particular Ac, more particularly with P’ being constituted of or comprising at least two units chosen from -SFlb’-, -SF2a’-, -SF2b’- and -SF3a’-, at least two of these units being different, wherein R1-R9 and R’9, Pi, P2, P3, and P4 are as defined above, and wherein Q’ is H, All, or LZ as defined above, and, for SFlb’, wherein R3 may also represent Bn.

[0180] In a particular embodiment, the invention also concerns a polysaccharide compound as defined above, being a homopoly-pentasaccharide of formula R2-P’-OQ’, wherein P’ is constituted of or comprises at least two units, and in particular at most 6 units, more particularly 2 or 3, of formula -SFlb’-, -SF2a’-, -SF2b’- or -SF3a’, R2 and Q’ being as defined above.

[0181] In a particular embodiment, the invention also concerns a polysaccharide compound as defined above, being a heteropoly-pentasaccharide (or chimeric poly-pentasaccharide) of formulaR2-P’-OQ’, wherein P’ is constituted of or comprises at least two units, and in particular at most 6 units, more particularly 2, 3, 4 or 5, chosen from -SFlb’-, -SF2a’-, -SF2b’- and - SF3a’-, at least two of these units being different.

[0182] By “poly-pentasaccharide”, is in particular meant: a poly- pentasaccharide constituted by pentasaccharides only; a poly- pentasaccharide comprising at least one tetrasaccharide; or a poly- pentasaccharide comprising at least one hexasaccharide.

[0183] In a particular embodiment, the invention also concerns a polysaccharide compound as defined above, which is selected from the following poly-pentasaccharides: R2-[(SF2a’)x-(SF3a’)y-(SFlb’)z]n-OQ’;

[0184] R2-[(SF2a’)x-(SFlb’)z-(SF3a’)y]n-OQ’;

[0185] R2-[(SF3a’)y-(SF2a’)x-(SFlb’)z]n-OQ’; R2-[(SF3a’)y-(SFlb’)z-(SF2a’)x]n-OQ’;

[0186] R2-[(SFlb’)z-(SF3a’)y-(SF2a’)x]n-OQ’;

[0187] R2-[(SFlb’)z-(SF2a’)x-(SF3a’)y]n-OQ’; wherein x, y and z are independently chosen from 0, 1 and 2, with at least two of x, y and z being 1 or 2.

[0188] In a particular embodiment, the invention also concerns a polysaccharide compound as defined above, which is selected from the following poly-pentasaccharides: R2-[SFlb’]n-OQ’; wherein n is in particular from 2 to 6, more particularly 2 or 3; R2-[SF2a’]n-OQ’; wherein n is in particular from 2 to 6, more particularly 2 or 3; R2-[SF3a’]n-OQ’; wherein n is in particular from 2 to 6, more particularly 2 or 3; R2-[SF2a’-SFlb’]n-OQ’; wherein n is in particular 1;

[0189] R2-[(SF2a’)2-SFlb’]n-OQ’; wherein n is in particular 1;

[0190] R2-[(SF2a’)2-(SFlb’)2]n-OQ’; wherein n is in particular 1;

[0191] R2-[SF3a’-SFlb’]n-OQ’; wherein n is in particular 1;

[0192] R2-[(SF3a’)2-SFlb’]n-OQ’; wherein n is in particular 1;

[0193] R2-[SF3a’-SF2a’]n-OQ’; wherein n is in particular 1;

[0194] R2-[SF2a’-SF3a’]n-OQ’; wherein n is in particular 1;

[0195] R2-[(SF2a’)2-SF3a’]n-OQ’; wherein n is in particular 1;

[0196] R2-[(SF2a’)2-(SF3a’)2]n-OQ’; wherein n is in particular l;R2-[SF3a’-(SF2a’)2]n-OQ’; wherein n is in particular 1;

[0197] R2-[(SF3a’)2-(SF2a’)2]n-OQ’; wherein n is in particular 1;

[0198] R2-[SF3a’-SF2a’-SFlb’]n-OQ’; wherein n is in particular 1;

[0199] R2-[SF3a’-(SF2a’)2-SFlb’]n-OQ’; wherein n is in particular 1; R2-[SF2a’-SF3a’-SFlb’]n-OQ’; wherein n is in particular 1; R2-[(SF2a’)2-(SF3a’)2-SFlb’]n-OQ’; wherein n is in particular 1; R2-[(SF3a’)2-(SF2a’)2-SFlb’]n-OQ’; wherein n is in particular 1; wherein:

[0200] Q’ is H, All, or LZ as defined above;

[0201] SFlb’, SF2a’, and SF3a’ are as defined above.

[0202] In a particular embodiment, the invention also concerns a polysaccharide compound as defined above, wherein P’ is constituted of or comprises at least two units chosen from -SFlb’- , -SF2a’-, -SF2b’-, -SF3a’- and -ABCD’- (SFY’) of following formula:

[0203]

[0204] (SFY’), wherein Ri and R3-R9 are as defined above,

[0205] P’ comprising at least one unit, in particular at least two units chosen from -SFlb’-, -SF2a’-, - SF3a’-, and at least one and -ABCD’- unit (SFY’ unit), in particular one -ABCD’- unit, more particularly between two units chosen from -SFlb’-, -SF2a’-, -SF2b’-, -SF3a’-.

[0206] The ABCD unit may be seen as the RU of the SFY serotype.

[0207] Said ABCD unit is optionally (9-acetylated in position 3A and / or 6D.

[0208] In a particular embodiment, the invention also concerns a polysaccharide compound as defined above, which is selected from the following polysaccharides: R2-[SF2a’-ABCD’-SF3a’]n-OQ’;

[0209] R2-[SF2a’-ABCD’-SFlb’]n-OQ’; wherein: n is 1;

[0210] Q’ is H, All, or LZ as defined above;

[0211] SFlb’, SF2a’, and SF3a’ are as defined above.

[0212] In another aspect, the invention also concerns a process of preparation of a polysaccharide as defined above, comprising: a) a step of contacting a penta- or hexasaccharide acceptor compound of formula (IIIA) or (IIIAF), or an ABCD’ acceptor, and a penta- or hexasaccharide donor compound of formula (IIID) or an ABCD’ donor; and optionally: b) a step: of converting the polysaccharide obtained in a previous step into an acceptor by deprotecting the R2group, in particular using hydrazine acetate or hydrazine in a mixture pyridine / acetic acid, in particular in a 1 : 1 (v / v) pyridine / acetic acid mixture when R2 is Lev; or of converting the polysaccharide obtained in a previous step into a donor by first deprotecting the All group, in particular using PdCl2and then NIS, or using hydrogen-activated (bis(methyldiphenylphosphine)) 1,5 -cyclooctadiene) iridium (I) hexafluorophosphate in place of PdCl2, and then of contacting the obtained compound with a compound of type D’-LG wherein D’ is a donor group and LG is a leaving group, for example PTFA-C1 when D’ is PTFA; and c) a step of contacting the acceptor or donor obtained in step b) with a penta- or hexasaccharide donor compound of formula (IIID) or an ABCD’ donor; or a penta- or hexasaccharide acceptor compound of formula (IIIA) or (IIIAF) or an ABCD’ acceptor, respectively, or an acceptor or donor obtained in one of the previous steps, respectively; step b) and c) being repeated if necessary; and / or d) a step of functionalizing if necessary the polysaccharide obtained in a previous step by deprotecting the All group, in particular using PdCl2and then NIS, or using hydrogen- activated (bis(methyldiphenylphosphine)) 1,5-cyclooctadiene) iridium (I) hexafluorophosphate in place of PdCl2, contacting the obtained compound with a compound of type D’-LG wherein D’ is a donor group and LG is a leaving group, for example PTFA-C1 when D’ is PTFA, and then contacting the obtained donor with a compound of formula HO-LZ, in particular in presence of TMSOTf, TfOH, TBSOTf, AgOTf, Tf2O, Bi(OTf)3, Yb(OTf)3, I2 / Et3SiH, TMSB(C6F5)4, acid-washed molecular sieves, ZnBr2, or BF3-Et2O, notably in catalytical conditions; step d) taking place after step c), or after one of steps c) if step c) is repeated), in particular after last step c).

[0213] In a particular embodiment, the invention also concerns a process of preparation of a polysaccharide as defined above, comprising: a) a step of contacting a penta- or hexasaccharide acceptor compound of formula (IIIA), or an ABCD’ acceptor, and a penta- or hexasaccharide donor compound of formula (IIID) or an ABCD’ donor; and optionally: b) a step: of converting the polysaccharide obtained in a previous step into an acceptor by deprotecting the R2 group, in particular using hydrazine acetate or hydrazine in a mixture pyridine / acetic acid, in particular in a 1 : 1 (v / v) pyridine / acetic acid mixture when R2 is Lev; or of converting the polysaccharide obtained in a previous step into a donor by first deprotecting the All group, in particular in particular using PdCL and then NIS, or using hydrogen-activated (bis(methyldiphenylphosphine)) 1,5 -cyclooctadiene) iridium (I) hexafluorophosphate in place of PdCh, and then of contacting the obtained compound with a compound of type D’-LG wherein D’ is a donor group and LG is a leaving group, for example PTFA-C1 when D’ is PTFA; and c) a step of contacting the acceptor or donor obtained in step b) with a penta- or hexasaccharide donor compound of formula (IIID) or an ABCD’ donor; or a penta- or hexasaccharide acceptor compound of formula (IIIA) or an ABCD’ acceptor, respectively, or an acceptor or donor obtained in one of the previous steps, respectively; step b) and c) being repeated if necessary; and comprising: d) a step of functionalizing if necessary the polysaccharide obtained in a previous step by deprotecting the All group, in particular using PdCh and then NIS, or using hydrogen- activated (bis(methyldiphenylphosphine)) 1,5-cyclooctadiene) iridium (I) hexafluorophosphate in place of PdCh, contacting the obtained compound with a compound of type D’-LG wherein D’ is a donor group and LG is a leaving group, for example PTFA-C1 when D’ is PTFA, and then contacting the obtained donor with a compound of formula HO-LZ, in particular in presence of TMSOTf, TfOH, TBSOTf, AgOTf, Tf2O, Bi(OTf)3, Yb(OTf)3, I2 / Et3SiH, TMSB(C6F5)4, acid-washed molecular sieves, ZnBr2, or BF3-Et2O, notably in catalytical conditions; step d) taking place after step c), or after the last of steps c) if step c) is repeated).

[0214] In a particular embodiment, the invention also concerns a process of preparation of a polysaccharide as defined above, being a poly-pentasaccharide comprising: a) a step of contacting a penta- or hexasaccharide acceptor compound of formula (IIIA) or (IIIAF) and a penta- or hexasaccharide donor compound of formula (IIID); and optionally: b) a step: of converting the poly-pentasaccharide obtained in a previous step into an acceptor by deprotecting the R2 group, in particular using hydrazine acetate or hydrazine in a mixture pyridine / acetic acid, in particular in a 1 : 1 (v / v) pyridine / acetic acid mixture when R2 is Lev; or of converting the poly-pentasaccharide obtained in a previous step into a donor by first deprotecting the All group, in particular in particular using PdCh and then NIS, or using hydrogen-activated (bis(methyldiphenylphosphine)) 1,5-cyclooctadiene) iridium (I) hexafluorophosphate in place of PdCh, and then of contacting the obtained compound with a compound of type D’-LG wherein D’ is a donor group and LG is a leaving group, for example PTFA-C1 when D’ is PTFA; and c) a step of contacting the acceptor or donor obtained in step b) with a penta- or hexasaccharide donor compound of formula (IIID) or a penta- or hexasaccharide acceptor compound of formula (IIIA) or (IIIAF), respectively, or an acceptor or donor obtained in one of the previous steps, respectively; step b) and c) being repeated if necessary; and / or d) a step of functionalizing if necessary the poly-pentasaccharide obtained in a previous step by deprotecting the All group, in particular using PdCh and then NIS, or using hydrogen-activated (bis(methyldiphenylphosphine)) 1,5-cyclooctadiene) iridium (I) hexafluorophosphate in place of PdCh, contacting the obtained compound with a compound of type D’-LG wherein D’ is a donor group and LG is a leaving group, for example PTFA-C1 when D’ is PTFA, and then contacting the obtained donor with a compound of formula HO-LZ, in particular in presence of TMSOTf, TfOH, TBSOTf, AgOTf, ThO, Bi(OTf)3, Yb(OTf)3, I2 / Et3SiH, TMSB(C6F5)4, acid-washed molecular sieves, ZnBr2, or BF3-Et2O, notably in catalytical conditions; step d) taking place after step c), or after one of steps c) if step c) is repeated), in particular after last step c).

[0215] In a particular embodiment, the invention also concerns a process of preparation of a polysaccharide as defined above, comprising: a) a step of contacting a penta- or hexasaccharide acceptor compound of formula (IIIA), and a penta- or hexasaccharide donor compound of formula (IIID) or an ABCD’ donor; and optionally: b) a step: of converting the polysaccharide obtained in a previous step into an acceptor by deprotecting the R2 group, in particular using hydrazine acetate or hydrazine in a mixture pyridine / acetic acid, in particular in a 1 : 1 (v / v) pyridine / acetic acid mixture when R2 is Lev; or of converting the polysaccharide obtained in a previous step into a donor by first deprotecting the All group, in particular in particular using PdCL and then NIS, or using hydrogen-activated (bis(methyldiphenylphosphine)) 1,5 -cyclooctadiene) iridium (I) hexafluorophosphate in place of PdCh, and then of contacting the obtained compound with a compound of type D’-LG wherein D’ is a donor group and LG is a leaving group, for example PTFA-C1 when D’ is PTFA; and c) a step of contacting the acceptor or donor obtained in step b) with a penta- or hexasaccharide donor compound of formula (IIID); or a penta- or hexasaccharide acceptor compound of formula (IIIA), respectively, or an acceptor or donor obtained in one of the previous steps, respectively; step b) and c) being repeated if necessary; and comprising: d) a step of functionalizing if necessary the polysaccharide obtained in a previous step by deprotecting the All group, in particular using PdCh and then NIS, or using hydrogen- activated (bis(methyldiphenylphosphine)) 1,5-cyclooctadiene) iridium (I) hexafluorophosphate in place of PdCh, contacting the obtained compound with a compound of type D’-LG wherein D’ is a donor group and LG is a leaving group, for example PTFA-C1 when D’ is PTFA, and then contacting the obtained donor with a compound of formula HO-LZ, in particular in presence of TMSOTf, TfOH, TBSOTf, AgOTf, Tf2O, Bi(OTf)3, Yb(OTf)3, I2 / Et3SiH, TMSB(C6F5)4, acid-washed molecular sieves, ZnBr2, or BF3-Et2O, notably in catalytical conditions; step d) taking place after step c), or after the last of steps c) if step c) is repeated).

[0216] In a particular embodiment, the invention also concerns a process as defined above, further comprising a step of conversion of the Ri protecting group into an acetyl group (Ac), on one, some or all of the donors and acceptors before their use, in particular on one, some or all of the penta- or hexasaccharide acceptor compounds of formula (IIIA) or (IIIAF) and penta- or hexasaccharide donor compounds of formula (IIID) before their use.

[0217] In a particular embodiment, the invention also concerns a process as defined above, further comprising: after the corresponding deprotection, a step of O-acetylation of the 3A position and / or the 6D position to obtain a 3A- and / or 6o-O-acetylated compound, in particular in 3A and 6D for SF2a, 3A for SFlb, in 6D for SF3a, and in 3A and in 6D for SFY; a step of cleavage of the CA or BA protecting group borne by C to obtain a 2c- hydroxylated compound, said step being optionally followed by an acetylation; and / or a step of hydrodechlorination / hydrodebromination of the CA or BA protecting group borne by C, respectively, in the frame of the final (full) deprotection step, to obtain a 2c-O-acetylated compound; a conversion of the A-masking group borne by D’ into an acetyl group (Ac), in particular when the masking group is not ChAc.

[0218] In particular, 2c-Ac may be introduced at the level of the protected pentasaccharide, for example in case mixtures with serotypes lacking 2c-Ac are contemplated, or at the final (full) deprotection stage, if, for example, homo SF3a polysaccharides

[0219] In another aspect, the invention also concerns a process of preparation of a glycoconjugate of formula H-P-OLZ’, wherein:

[0220] P is constituted of or comprises at least two units chosen from -SFlb-, -SF2a-, -SF2b-, -SF3a- (or -SFX-, as mentioned above) and -ABCD- (SFY), wherein:

[0221] SFlb is ABC(E)D, SF2a is AB(E)CD, SF2b is (E)AB(E)CD, SF3a is (E)ABCD, with A is 2)- a-l.-Rha / 9-( l ^ , B is 2)-a-L-Rha / ?-(l^ , C is 3)-a-L-Rha / ?-(l^ , D is 3)-P-D-GlcpNAc-(l^, or, when D is in terminal position, 3)-P-D-GlcpNAc-(l^- or 3)-a-D-GlcpNAc-(l^-, E represents a residue a-D-Glcp-;

[0222] L is: a single bond, a divalent C1-C12 alkyl, C2-C12 alkenyl or C2-C12 alkynyl chain optionally interrupted by one or more heteroatoms, notably selected from an oxygen atom, a sulphur atom or a nitrogen atom, said nitrogen and sulphur atoms being optionally oxidized, and the nitrogen atom being optionally involved in an acetamide bond, or a divalent C1-C12 alkyl, C2-C12 alkenyl or C2-C12 alkynyl chain substituted by at least one -OH group, being in particular of the following formula -(CH2-CH2-C(OH))q- (CH2-CH2)i, wherein i is 0 or 1 and q ranges from 1 to 10,

[0223] Z’ is Zi or F1-L2-Z2, Zi is a terminal function or group, optionally protected, able to form a covalent bond with a carrier and / or a solid support, or a multivalent scaffold; an anchor; a mono-, oligo- or polysaccharide; or a dye or fluorescent residue.

[0224] Fi is any group enabling to bond the linker L to the linker L2, Fi being in particular chosen from the -C(O)-, -C(O)-C(O)-, -C(O)-C(O)-NH-, -NHC(O)-C(O)-, -NHC(0)-C(0)-NH-, -C(O)- C(H)=N-NH-, -NH-C(O)-C(H)=N-NH-, ester, amide, amine, -CH2-, ether, thioether, imine, thiosuccinimide, oxime, hydrazone, hydrazonamide, -C(O)CH2-NH-, -NH-CH2-C(O)-, triazole functions or groups, and from the following: single bond, divalent C1-C12 alkyl,

[0225] C2-C12 alkenyl or C2-C12 alkynyl chain optionally interrupted by one or more heteroatoms, notably selected from an oxygen atom, a sulphur atom or a nitrogen atom, said nitrogen and sulphur atoms being optionally oxidized, and the nitrogen atom being optionally involved in an acetamide bond,

[0226] Z2 is Zi or F2-L3-Zi,

[0227] F2 is any group enabling to bond the linker L to the linker L3, Fi being in particular chosen from the -C(O)-, -C(O)-C(O)-, -C(O)-C(O)-NH-, -NHC(O)-C(O)-, -NHC(O)-C(O)-NH-, -C(O)- C(H)=N-NH-, -NH-C(O)-C(H)=N-NH-, ester, amide, amine, -CH2-, ether, thioether, imine, thiosuccinimide, oxime, hydrazone, hydrazonamide, -C(O)CH2-NH-, -NH-CH2-C(O)-, triazole functions or groups, and from the following: single bond, a divalent C1-C12 alkyl,

[0228] C2-C12 alkenyl or C2-C12 alkynyl chain optionally interrupted by one or more heteroatoms, notably selected from an oxygen atom, a sulphur atom or a nitrogen atom, said nitrogen and sulphur atoms being optionally oxidized, and the nitrogen atom being optionally involved in an acetamide bond, said process comprising: a) One or more steps of full deprotection of a polysaccharide of formula R2-P’-LZ as defined above, to obtain a H-P-OLZi compound or a H-P-OLFi compound, L and Zi being as defined above, Ff being a precursor of Fi as defined above; b) Optionally, a step of contacting the fully deprotected polysaccharide obtained in the previous step with: - a compound of following formula FI”-L2-ZI, Fi” being a precursor of Fi as defined above, L2 and Zi being as defined above, or

[0229] - a compound of following formula FI”-L2-F2’, Fi” being a precursor of Fi as defined above, F2’ being a precursor of F2 as defined above, L2 being as defined above, followed by contacting the obtained compound with a compound of following formula F2”-L3-ZI, wherein F2” is a precursor of F2 as defined above, and L3 and Zi being as defined above.

[0230] The LZ group may be of one of the following formulae:

[0231] - L-Zi;

[0232] - L-F1-L2-Z1; or

[0233] L-F1-L2-F2-L3-Z1.

[0234] The above or below mentioned units, in particular the -SFlb-, -SF2a-, -SF2b-, -SF3a-, -SFY- units, are optionally (9-acetylated, said (9-acetylation being partial or stoichiometric.

[0235] In a particular embodiment, Zi is a terminal reactive function or group, optionally protected, able to form a covalent bond with a carrier and / or a solid support.

[0236] In particular embodiment, the carrier and / or a solid support presents on its surface functionalities, more particularly primary amino functionalities, notably of lysine residues, that are able to react with Zi.

[0237] In another particular embodiment, the carrier and / or a solid support presents on its surface functionalities, more particularly primary amino functionalities, notably of lysine residues, linked to an interconnecting molecule, which is able to react with the Zi group of the oligo- and polysaccharides of the invention.

[0238] In a particular embodiment, Zi is a multivalent scaffold; an anchor; a mono-, oligo- or polysaccharide; or a dye or fluorescent residue.

[0239] In a particular embodiment, L2 is a single bond, and Fi and Z2 or Zi are one and only group.

[0240] In a particular embodiment, L3 is a single bond, and F2 and Zi are one and only group.

[0241] By anchor is in particular meant a residue able to form a non-covalent type attachment with a carrier and / or a solid support. Said anchor is for example biotin, able to form non- covalent bonds with streptavidin bound to a solid support.

[0242] By multivalent scaffold is in particular meant a scaffold able to form at least two bonds, each one with one compound of formula (II) of the present invention. Said multivalent scaffold is for example a linear polymer, a dendrimer, a monosaccharide, a cyclic peptide, or a (poly)- lysine scaffold.

[0243] In a particular embodiment, Zi is a terminal reactive function or group, optionally protected, able to form a covalent bond with a carrier and / or a solid support.

[0244] Fi’ and Fi” are for example:

[0245] - -C(O)-C(O)OH and an amine, forming a -C(O)-C(O)-NH- group (Org. Lett. 2023, 25,

[0246] 5117-5122),

[0247] - -C(O)-C(O)H and a hydrazine, forming a -C(O)-C(H)=N-NH- group,

[0248] - A carboxylic acid or an activated ester and an alcohol, forming an ester,

[0249] - an activated ester and an amine, forming an amide,

[0250] - an amine and a leaving group, forming an amine,

[0251] - a thiol and a leaving group, forming thioether,

[0252] - a thiol and an allyl,

[0253] - an amine and an aldehyde, forming an imine,

[0254] - an amine and an aldehyde, forming an amine, in particular by reductive amination,

[0255] - a thiol and a maleimide, forming a thiosuccinimide,

[0256] - an azide and an alkyne, forming a triazole, in particular by click chemistry,

[0257] - C(O)CH2-Hal, in particular Br, and an amine, forming a C(O)CH2-NH group,

[0258] - NHC(O)CH2-Hal, in particular Br, and an amine, forming a NHC(O)CH2-NH group,

[0259] - C(O)CH2-Hal, in particular Br, and a thiol, forming a C(O)CH2-SH group,

[0260] - NHC(O)CH2-Hal, in particular Br, and a thiol, forming a NHC(O)CH2-SH group,

[0261] F2’ and F2” are for example:

[0262] - -C(O)-C(O)OH and an amine, forming a -C(O)-C(O)-NH- group,

[0263] - -C(O)-C(O)H and a hydrazine, forming a -C(O)-C(H)=N-NH- group,

[0264] - A carboxylic acid or an activated ester and an alcohol, forming an ester,

[0265] - an activated ester and an amine, forming an amide,

[0266] - an amine and a leaving group, forming an amine,

[0267] - a thiol and a leaving group, forming thioether, - a thiol and an allyl,

[0268] - an amine and an aldehyde, forming an imine,

[0269] - an amine and an aldehyde, forming an amine, in particular by reductive amination,

[0270] - a thiol and a maleimide, forming a thiosuccinimide,

[0271] - an azide and an alkyne, forming a triazole, in particular by click chemistry,

[0272] - C(0)CH2-Hal, in particular Br, and an amine, forming a C(0)CH2-NH group,

[0273] - NHC(0)CH2-Hal, in particular Br, and an amine, forming a NHC(0)CH2-NH group,

[0274] - C(0)CH2-Hal, in particular Br, and a thiol, forming a C(O)CH2-SH group,

[0275] - NHC(0)CH2-Hal, in particular Br, and a thiol, forming a NHC(0)CH2-SH group,

[0276] Reference is also made regarding glyoxylyl group to Bioconjugate Chem. 2013, 24, 735-765

[0277] In a particular embodiment, Fi” and F2’ are orthogonal (i.e. in particular they do react together).

[0278] In a particular embodiment, L is a divalent C1-C12 alkyl or alkenyl chain optionally interrupted by one or more heteroatoms, notably selected from an oxygen atom, a sulphur atom or a nitrogen atom, said nitrogen and sulphur atoms being optionally oxidized, and the nitrogen atom being optionally involved in an acetamide bond, and Ff is before deprotection a N3, NHCbz, or NBnCbz group, L-F 1 ’ being before deprotection notably a PEG chain bearing a N3, NHCbz, NBnCbz, or SBn group (for this latter, see for example Chem. Sci. 2014, 5, 1992).

[0279] In a particular embodiment, the Ff group reacts with FI”-L2-ZI which is a compound bearing a first reactive function that will react with the Ff residue to form the Fi function. In a particular embodiment, the Ff group reacts with FI”-L2-F2’ that further comprises a second reactive function F2’, which is orthogonal to the first reactive function Fi”.

[0280] In a more particular embodiment, L-Zi or L-Fi’ is -(CE[2)p-NH3+or -(CH2)P-NH2, wherein p ranges from 1 to 10, in particular from 2 to 8, more particularly 2, 3, 4, 5 or 6, and FI”-L2-ZI or FI”-L2-F2’ is an activated version, in particular an activated ester of the compound of the following formula:

[0281] In another more particular embodiment, HO-L-Zi or HO-L-Fi’ is HO-(CH2)P-CH2=CH2, and FI”-L2-ZI is a thiol, for example HS-Bn. Reference is in particular made to Angew. Chem. Int. Ed. 2014, 53, 3894 -3898.

[0282] In another more particular embodiment, L-Zi or L-Fi’ is -(CH2)P-SH (reference is in particular made for this latter case to Chem. Eur. J. 2004, 10, 4265 - 4282), wherein p ranges from 1 to 10, in particular from 2 to 8, more particularly 2, 3, 4, 5 or 6.

[0283] In a particular embodiment, L-Zi or L-Fi’ is -(CH2)P-OH, wherein p ranges from 1 to 10, in particular from 2 to 8, more particularly 2, 3, 4, 5 or 6. The introduced primary alcohol may for example be converted into an aldehyde moiety upon selective oxidation, and then react with a FI”-L2-ZI or FI”-L2-F2’ compound comprising a hydrazide-, an oxime- or a derivative. FI”-L2-ZI or FI”-L2-F2’ optionally further comprises a second reactive function, which is orthogonal to the first reactive function, and may be selected from alkene, alkyne and masked thiol groups.

[0284] In a particular embodiment, L-Zi or L-Fi’ is -CH2-C(OH)-CH2-OH, and FI”-L2-ZI or FI”-L2-F2’ is of the following formula:

[0285] In another aspect, the invention also concerns a glycoconjugate of formula H-P-OLZ’, as defined above, wherein P is constituted of or comprises: at least two different units chosen from -SFlb-, -SF2a-, -SF2b-, -SF3a-; at least one -SFlb- unit, with LZ’ being different from propyl when P is constituted of or comprises one -SFlb- unit; or at least one -ABCD- unit (-SFY- unit), in particular one -ABCD- unit, and at least one unit chosen from -SFlb-, -SF2a-, -SF2b-, -SF3a-,

[0286] And wherein:

[0287] - the ABCD units are optionally substituted by at least one phosphoethanolamine (PEtN-modified); and / or

[0288] - the units, in particular the -SFlb-, -SF2a-, -SF2b-, -SF3a-, -SFY- units are optionally (9-acetylated, said (9-acetylation being partial or stoichiometric. In a particular embodiment, the invention also concerns a glycoconjugate as defined above, being of one of the following formulae:

[0289] H-[SFlb]n-OLZ’;

[0290] H-[SF2a-SFlb]n-OLZ’;

[0291] H-[(SF2a)2-SFlb]n-OLZ’;

[0292] H-[(SF2a)2-(SFlb)2]n-OLZ’;

[0293] H-[SF3a-SFlb]n-OLZ’;

[0294] H-[(SF3a)2-SFlb]n-OLZ’;

[0295] H-[SF3a-SF2a]n-OLZ’;

[0296] H-[SF2a-SF3a]n-OLZ’;

[0297] H-[(SF2a)2-SF3a]n-OLZ’;

[0298] H-[(SF2a)2-(SF3 a)2]n-OLZ ’ ;

[0299] H-[SF3a-(SF2a)2]n-OLZ’;

[0300] H-[(SF3a)2-(SF2a)2]n-OLZ’;

[0301] H-[SF3a-SF2a-SFlb]n-OLZ’;

[0302] H-[SF3a-(SF2a)2-SFlb]n-OLZ’;

[0303] H-[SF2a-SF3a-SFlb]n-OLZ’;

[0304] H-[(SF2a)2-(SF3 a)2-SF 1 b]n-OLZ ’ ;

[0305] H-[SF2a-ABCD-SF3a]n-OLZ’;

[0306] H-[SF2a-ABCD-SFlb]n-OLZ’.

[0307] And wherein:

[0308] - the ABCD units are optionally substituted by at least one phosphoethanolamine (PEtN-modified); and / or

[0309] - the units, in particular the -SFlb-, -SF2a-, -SF3a-, -SFY- units are optionally O- acetylated, said acetylation being partial or stoichiometric, -SF3a- being in particular stoichiometrically (9-acetylated in position 2c, or not (9-acetylated in position 2c (corresponding to SFX), -SFlb- being in particular (9-acetylated, more particularly partially, in position 2c, and / or possibly in position 3A and / or 4A, -SFY- being in particular (9-acetylated in position 3A and / or 6D, -SF2a- being in particular (9-acetylated, more particularly in position 3A and / or 4A.

[0310] In a particular embodiment, the glycoconjugate is H-[SFlb]n-OLZ’, which is partially (9-acetylated.

[0311] In a particular embodiment, the glycoconjugate is H-[SFlb]n-OLZ’, which is partially (9-acetylated, in particular on position 2c. In a particular embodiment, the glycoconjugate is H-[SFlb]n-OLZ’, which is O- acetylated, in particular on position 2c, when n=l, or (9-acetylated or partially (9-acetylated, in particular on position 2c, when n is not 1.

[0312] Such (9-acetylation is for example described in FEMS Immunol. Med. Microbiol. 2012, 66, 201, and Biochemistry (Moscow), 2015, 80, 7, 901-914 and Biochemistry (Moscow), 2015, 80, 7, 1072-1087.

[0313] In another aspect, the invention also concerns a glycoconjugate of formula H-P-OLZ’, as defined above, wherein P is constituted of or comprises at least one -SF2a- or -SF3a- units.

[0314] In a particular embodiment, the number of -SF2a- or -SF3a- units is 3 or 4 or more, and in particular less than 100, 50, 20, or 10.

[0315] In a particular embodiment, the number of -SF2a- or -SF3a- units is 1, 2 or 3, and LZ’ is different from propyl, aminoethyl and aminopropyl.

[0316] In a particular embodiment, the number of -SF3a- units is 1, 2 or 3, and LZ’ is different from propyl, aminoethyl and aminopropyl.

[0317] In a particular embodiment, the number of -SF3a- units is 1, 2 or 3, and LZ’ is different from aminoethyl and aminopropyl.

[0318] In another aspect, Zi is a terminal function or group, forming a covalent bond with a carrier and / or a solid support, or a multivalent scaffold; an anchor; a mono-, oligo- or polysaccharide; or a dye or fluorescent residue, an adjuvant.

[0319] Covalent linkage of synthetic oligo- and polysaccharides to proteins is known in the art and may for example be achieved by targeting the s-amines of lysines, the carboxylic groups of aspartic / glutamic acids, the sulfhydryls of cysteines, or tyrosines. A reactive group, for example an amine, can also be introduced at the oligosaccharide reducing termini, directly or via a linker, to be used finally for insertion of a bifunctional linker for conjugation to the carrier.

[0320] For example, the oligo- or polysaccharide may be conjugated to the carrier through the reaction between a maleimido or haloacetyl group, in particular bromoacetyl group, bound to the oligo- or polysaccharide, in particular via a linker, and a thiol or a NH2 group bound to the carrier, in particular via a linker; or through the reaction between a maleimido or haloacetyl group, in particular bromoacetyl group, bound to the carrier, in particular via a linker, and a thiol or a NH2 group bound to the oligo- or polysaccharide, in particular via a linker.

[0321] To conjugate with a linker or crosslinking agent, either or both of the oligo- or polysaccharide and the carrier may be covalently bound to one or more linkers first. The linkers or crosslinking agents are homobifunctional or heterobifunctional molecules, e.g., adipic dihydrazide, ethylenediamine, cystamine, 7V-succinimidyl 3-(2-pyridyldithio)propionate (SPDP), A-acetyl-DL-homocysteine thiolactone, A’-succinimidyl-[A-(2-iodoacetyl)-P-alanyl] propionate (SIAP), 3,3’-dithiodipropionic acid, squarates and their derivatives, and the like.

[0322] According to the type of linkage between the oligo- or polysaccharide and the carrier, there is the possibility of preparing a conjugate wherein the ratio of the oligo- or polysaccharide versus the carrier can in particular vary between 1 : 1 and 500: 1, notably between 1 : 1 and 200: 1. More particularly, this ratio is comprised between 1 : 1 and 30: 1, preferably between 5: 1 and 25: 1, more preferably between 8: 1 and 30: 1, or between 5: 1 and 20: 1, notably when the carrier is tetanus toxoid or a fragment thereof.

[0323] A carrier can be a natural, modified-natural, synthetic, semi -synthetic or recombinant material containing one or more functional groups, for example primary and / or secondary amino groups, azido groups, thiol, alkynyl, alkenyl, or carboxyl group. The carrier can be water soluble or insoluble. Carriers that fulfil these criteria are well-known to those of ordinary skill in the art.

[0324] Suitable carriers according to the present invention notably include proteins, peptides, lipopeptides, said proteins, peptides and lipopeptides incorporating possibly non-canonical amino acids, zwitterionic polysaccharides, lipid aggregates (such as oil droplets or liposomes), inactivated virus particles, nanoparticles, in particular gold nanoparticles (reference is for example made to Bioorg. Chem. 2020, 99, 103815, ox Nanomedicine 2012, 7, 651-662), viruslike particles, for example bacteriophage QP (VLP s Methods EnzymoL 2017, 597, 359-376) and Generalized Modules for Membrane Antigens (GMMA; reference is for example made to: Vaccines 2020, 8, 540; Vaccines (Basel) 2020 8, 160), non-covalent conjugates, in particular non-covalent conjugates based on a binding between a biotinylated antigen and a carrier conjugated to an avidin-type protein such as exemplified by the Multiple Antigen Presenting System (MAPS; reference is for example made to Proc. Natl. Acad. Sci. U S A. 2013, 110, 13564-13569, Exp. Rev. Vaccines 2024, 23, 196-204 ; Infect. Immun. 2022, 90, e0035221).

[0325] In a particular embodiment, the carrier is a protein, in particular native or not.

[0326] In this case, the term "carrier" refers in particular to a protein to which the oligo- or polysaccharide is coupled or attached or conjugated, typically for the purpose of enhancing or facilitating detection of the antigen by the immune system. Oligosaccharides are T-independent antigens that are poorly immunogenic and do not lead to long-term protective immune responses. Conjugation of the oligosaccharide antigen to a protein carrier changes the context in which immune effector cells respond to oligosaccharides. The term carrier protein is intended to cover both small peptides and large polypeptides (>10 kDa). In a particular embodiment, the carrier is an immunocarrier. Immunocarriers are carriers chosen to increase the immunogenicity of the oligo- or polysaccharide and / or to raise antibodies against the carrier which are medically beneficial.

[0327] Suitable immunocarriers according to the present invention notably include proteins, glycosphingolipids, peptides, lipopeptides, lipid aggregates containing T-helper peptides (at least one), inactivated virus particles, nanoparticles, in particular gold nanoparticles, and GMMA.

[0328] In a particular embodiment, the conjugate of the invention is covalently bound to a protein or a peptide comprising at least one T-helper epitope.

[0329] Protein carriers known to have potent T-helper epitopes, include but are not limited to bacterial toxoids such as tetanus, diphtheria and cholera toxoids, Staphylococcus exotoxin or toxoid, Pseudomonas aeruginosa Exotoxin A and recombinantly produced, genetically detoxified variants thereof, outer membrane proteins (OMPs) of Neisseria meningitidis and Shigella proteins. The recombinantly-produced, non-toxic mutant strains of P. aeruginosa Exotoxin A (rEPA) are described and used in polysaccharide-protein conjugate vaccines (Infect. Immun. 1993, 61, 1023-1032). The CMR197 carrier is a well characterized non-toxic diphtheria toxin mutant that is useful in glycoconjugate vaccine preparations intended for human use (a) Adv. Exp. Med. Biol. 1989, 257, 175-180; b) Vaccine 1992, 10, 691-698). Other exemplary protein carriers include the Fragment C of tetanus toxin (WO 2005 / 000346, WO 2005 / 000346) and recombinant 8MTT (Vaccines 2023, 11, 1770). Also, CRM9 carrier has been disclosed for human immunisation (Pediatr. Infect. Dis. J. 2003, 22, 701-706).

[0330] Useful carrier proteins include bacterial toxins or toxoids, such as diphtheria toxoid or tetanus toxoid. Fragments of toxins or toxoids can also be used e.g. fragment C of tetanus toxoid. The CRM197 mutant of diphtheria toxin is a particularly useful with the invention. Other suitable carrier proteins include the N. meningitidis outer membrane protein, synthetic peptides, heat shock proteins, pertussis proteins , cytokines, lymphokines, hormones, growth factors, human serum albumin (preferably recombinant) in particular for diagnostic aspects, artificial proteins comprising multiple human CD4+ T cell epitopes from various pathogen- derived antigens such as N19, protein D from Haemophilus influenzae, pneumococcal surface protein PspA, pneumolysin, iron-uptake proteins, toxin A or B from Clostridium difficile, recombinant P. aeruginosa exoprotein A (rEPA), a GBS protein, and the like.

[0331] Particularly suitable carrier proteins include CRM 197, tetanus toxoid (TT), tetanus toxoid fragment C, protein D, non-toxic mutants of tetanus toxin and diphtheria toxoid (DT). Other suitable carrier proteins include protein antigens GBS80, GBS67 and GBS59 from Streptococcus agalactiae and fusion proteins, for example, GBS59(6xD3) disclosed in WO201 1 / 121576 and GBS59(6xD3)-1523 disclosed in EP14179945.2. The use as other suitable carrier proteins of protein antigens that are common to several Shigella serotypes such as IpaD, IpaB, MxiH and all their possible combinations may also be advantageous. Another carrier could be genetically modified OMVs (GMMA). Synthetic peptides bearing immunodominant T-helper cell epitopes can also act as carriers in polysaccharide and oligosaccharide conjugates. The peptide carriers include polypeptides containing multiple T- helper epitopes addressing the extensive polymorphism of HLA molecules (Pediatrics 1993, 92, 827-832), and universal T-helper epitopes compatible with human use. Exemplary T-helper epitopes, include but are not limited to natural epitopes characterized from tetanus toxoid (J Immunol. 1992, 749, 717-721), and non-natural epitopes or engineered epitopes such as the pan HLA DR-binding epitope PADRE (Immunity 1994, 7, 751-761).

[0332] In a particular embodiment of the present invention, the immunocarrier is selected among a protein or a peptide comprising at least one T-helper epitope, or a derivative thereof. In a particular aspect, the immunocarrier is the peptide PADRE.

[0333] In a particular embodiment of the present invention, the immunocarrier is tetanus toxoid (TT) or a fragment thereof.

[0334] In another particular embodiment of the present invention, the immunocarrier is CRM197.

[0335] The term "toxoid" as used herein refers to a bacterial toxin (usually an exotoxin), whose toxicity has been inactivated or suppressed either by chemical (formalin) or heat treatment, while other properties, typically T-helper properties and / or immunogenicity, are maintained. A mutated toxoid as used herein is a recombinant bacterial toxin, which has been amended to be less toxic or even non-toxic by amending the wild-type amino acid sequence. Such a mutation could be a substitution of one or more amino acids. Such a mutated toxoid presents on its surface a functionality that can react with the functional group of the interconnecting molecule to provide a modified toxoid. Said functionality is known to the person skilled in the art and includes, but is not restricted to the primary amino functionality of a lysine residue that can react with activated esters, an isocyanate group or an aldehyde in presence of a reducing agent, to the carboxylate functionality of a glutamate or aspartate residue that can be activated by carbodiimides or to the thiol functionality of a cysteine residue.

[0336] Activated esters include, but are not restricted to A-(y-maleimidobutyryloxy) succinimide ester (GMBS), A-(y-maleimidobutyryloxy) sulfosuccinimide ester (sulfo-GMBS), succinimidyl (4-iodoacetyl)aminobenzoate (SIAB), sulfosuccinimidyl (4- iodoacetyl)aminobenzoate (sulfo-SIAB), succinimidyl 3-(bromoacetamido)propionate (SBAP), disuccinimidyl glutarate (DSG), disuccinimidyl adipate (DSA), 2 -pyridyl di thiol - tetraoxatetradecane-A-hydroxysuccinimide (PEG-4-SPDP), bis-(4-nitrophenyl) adipate and bis-(4-nitrophenyl) succinate. Preferred activated esters are for example N-(y- maleimidobutyryloxy) succinimide ester (GMBS), A-(y-maleimidobutyryloxy) sulfosuccinimide ester (sulfo-GMBS), succinimidyl (4-iodoacetyl)aminobenzoate (SIAB), sulfosuccinimidyl (4-iodoacetyl)aminobenzoate (sulfo-SIAB), succinimidyl-3- (bromoacetamido)propionate (SBAP).

[0337] The cysteine residue on the carrier protein can be converted to the corresponding dehydroalanine that can be further reacted with a suitable interconnecting molecule to provide modified carrier protein having on their surface the functional group of the interconnecting molecule.

[0338] For example, the inventive saccharides described herein are conjugated to the non-toxic mutated diphtheria toxin CRM 197 presenting as a functionality a primary amine functionality of a lysine residue.

[0339] CRM197 like wild-type diphtheria toxin is a single polypeptide chain of 535 amino acids (58 kD) consisting of two subunits linked by disulfide bridges having a single amino acid substitution of glutamic acid for glycine. It is utilized as a carrier protein in a number of approved conjugate vaccines for diseases such as Prevnar.

[0340] It is especially preferred that inventive saccharides described herein are conjugated to tetanus toxoid (TT) or a fragment thereof presenting as a functionality a primary amine functionality of a lysine residue.

[0341] It is especially preferred that inventive saccharides described herein are conjugated to CRM 197 presenting as a functionality a primary amine functionality of a lysine residue.

[0342] Thus, in a preferred embodiment of the present invention the carrier protein presents on its surface primary amino functionalities of lysine residues that are able to react with the functional group of the interconnecting molecule to provide modified carrier protein having on their surface said functional group of the interconnecting molecule, which is able to react with the Z group of the oligo- and polysaccharides of the invention.

[0343] Said functional group of the interconnecting molecules is for example selected from the group comprising or consisting of maleimide; a-iodoacetyl; a-bromoacetyl; and N- hydroxysuccinimide ester (NHS), aldehyde, imidoester, carboxylic acid, alkyl sulfonate, sulfonyl chloride, epoxide, anhydride, carbonate.

[0344] Other types of carrier include but are not limited to liposomes. As regards the use of a liposome as a carrier, in particular those, which do not imply covalent linkages between the glycan component and the T-helper component, reference could be made to the International Application WO 2010 / 136947.

[0345] In a particular embodiment of the present invention, the carrier is biotin (as an anchor) or biotin / avidin complex.

[0346] In a particular embodiment of the present invention, Zi is an adjuvant, for example PAMCys3 (Vaccine 2009, 7, 5419-5426).

[0347] In a particular embodiment of the present invention, the carrier is a multivalent scaffold, i.e. a carrier that enables multiple presentation of the oligo- or polysaccharide of the invention, in particular a scaffold able to form at least two bonds, each one with an oligo- or polysaccharide of the invention. Said multivalent scaffold is for example a linear polymer, a dendrimer, a monosaccharide, a cyclic peptide, or a (poly)-lysine scaffold, for example MAP (Multiple Antigen Peptide), as for example described in J. Immunol. Methods 1989, 124, 53-61.

[0348] Compositions may include a small amount of free carrier. When a given carrier protein is present in both free and conjugated form in a composition of the invention, the unconjugated form is preferably no more than 5% of the total amount of the carrier protein in the composition as a whole, and more preferably present at less than 2% by weight.

[0349] After conjugation, free and conjugated oligosaccharides can be separated. There are many suitable methods, including hydrophobic chromatography, tangential ultrafiltration, diafiltration, etc.

[0350] In another object, the invention provides an immunogenic composition comprising a conjugate according to the invention and a physiologically acceptable vehicle.

[0351] All the embodiments related to the conjugate apply here as well, alone or in combination.

[0352] The immunogenic (or vaccine) composition includes one or more pharmaceutically acceptable excipients or vehicles such as water, saline, glycerol, or ethanol. Additionally, auxiliary substances, such as wetting or emulsifying agents, pH buffering substances, and the like, may be present in such vehicles.

[0353] The glycoconjugates of the present invention which induce protective antibodies against S. flexneri infection are administered to a mammal subject, preferably a human, in an amount sufficient to prevent or attenuate the severity, extent of duration of the infection by S. flexneri.

[0354] Immunogenic compositions are suitable for administration to animal (and, in particular, human) subjects, and thus include both human and veterinary uses. They may be used in a method of raising an immune response in a subject, comprising the step of administering the composition to the subject. The immunogenic compositions of the present invention may be administered before a subject is exposed to a S. flexneri and / or after a subject is exposed to a S. flexneri.

[0355] Immunogenic compositions may be prepared in unit dose form. In some embodiments a unit dose may have a volume of between 0.1-1.0 mL e.g. about 0.5 mL.

[0356] The invention also provides a delivery device (e.g. syringe, nebulizer, sprayer, inhaler, dermal patch, etc.) containing an immunogenic composition of the invention e.g. containing a unit dose. This device can be used to administer the composition to a vertebrate subject.

[0357] The invention also provides a sterile container (e.g. a vial) containing an immunogenic composition of the invention e.g. containing a unit dose, or a multidose sterile container.

[0358] The invention also provides a unit dose of an immunogenic composition of the invention.

[0359] The invention also provides a hermetically sealed container containing an immunogenic composition of the invention. Suitable containers include e.g. a vial.

[0360] Immunogenic compositions of the invention may be prepared in various forms. For example, the immunogenic compositions may be prepared as injectables, either as liquid solutions or suspensions. Solid forms suitable for solution in, or suspension in, liquid vehicles prior to injection can also be prepared (e.g. a lyophilized composition or a spray -freeze dried composition). The composition may be prepared for topical administration e.g. as an ointment, cream or powder. The composition may be prepared for oral administration e.g. as a tablet or capsule, as a spray, or as a syrup (optionally flavored). The composition may be prepared for pulmonary administration e.g. by an inhaler, using a fine powder or a spray. The composition may be prepared as a suppository. The composition may be prepared for nasal, aural or ocular administration e.g. as a spray or drops. Injectables for intramuscular administration are typical.

[0361] The pharmaceutical compositions may comprise an effective amount of an adjuvant i.e. an amount which, when administered to an individual, either in a single dose or as part of a series, is effective for enhancing the immune response. This amount can vary depending upon the health and physical condition of the individual to be treated, age, the taxonomic group of individual to be treated (e.g. non-human primate, primate, etc.), the capacity of the individual's immune system to synthesize antibodies, the degree of protection desired, the formulation of the immunogenic composition, the treating doctor's assessment of the medical situation, and other relevant factors. The amount will fall in a relatively broad range that can be determined through routine trials.

[0362] Techniques for the formulation and administration of the immunogenic composition of the present invention may be found in "Remington's Pharmaceutical Sciences" Mack Publishing Co., Easton PA. Each vaccine dose comprises a therapeutically effective amount of oligo- or polysaccharide conjugate.

[0363] A therapeutically effective dosage of one conjugate according to the present invention or of one saccharide of general formula (I) refers to that amount of the compound that results in an at least partial immunization against a disease. Toxicity and therapeutic efficacy of such compounds can be determined by standard pharmaceutical, pharmacological, and toxicological procedures in cell cultures or experimental animals. The dose ratio between toxic and therapeutic effect is the therapeutic index. The actual amount of the composition administered will be dependent on the subject being treated, on the subject's weight, the severity of the affliction, the manner of administration and the judgement of the prescribing physician.

[0364] Such amount will vary depending on the capacity of the subject to synthesize antibodies against the oligo- or polysaccharide, the degree of protection desired, the particular oligo- or polysaccharide conjugate selected and its mode of administration, among other factors. An appropriate effective amount can be readily determined by one skilled in the art. A therapeutically effective amount may vary in a wide range that can be determined through routine trials.

[0365] More particularly the oligo- or polysaccharide conjugate of the invention will be administered in a therapeutically effective amount that comprises from 0.1 pg to 100 pg, notably from 0.5 pg to 50 pg of oligo- or polysaccharide, preferably 1 pg to 10 pg. An optimal amount for a particular vaccine can be ascertained by methods known from the skilled in the art, in particular standard studies involving measuring the anti-5, flexneri antibody titers in subjects, more accurately protective antibody titers.

[0366] Methods of administering the immunogenic compositions of the invention are well known from the skilled in the art. Briefly, the immunogenic compositions of the invention may be administered in single or multiple doses. The inventors have found that the administration of a single dose of the immunogenic compositions of the invention may be sufficient. Alternatively, one unit dose followed by a second unit dose may be effective. Typically, the second (or third, fourth, fifth etc.) unit dose is identical to the first unit dose. The second unit dose may be administered at any suitable time after the first unit dose, in particular after 1, 2 or 3 months. In particular, following an initial administration, subjects may receive one or two booster injections, for example at about four- week, one month, two months, three months, four months, five months and / or six months intervals. For infants less than 12 months of age, two doses at not less than two, three, four, five or six month(s) intervals can be administered, the first dose not being administered before 2 months of age. The immunogenic composition of the invention may include one or more adjuvants. However, the use of unadjuvanted compositions is also envisaged, for example, it may be advantageous to omit adjuvants in order to reduce potential toxicity, complexity and costs. Accordingly, immunogenic compositions that do not contain any adjuvant or that do not contain any aluminium salt adjuvant are envisaged.

[0367] Adjuvants generally combined with glycoconjugate vaccines allow to strengthen the antibody response and hence the B response. Adjuvants can be added directly to the vaccine compositions or can be administered separately, either concurrently with or shortly after, administration of the vaccine.

[0368] Adjuvants are well known from the person skilled in the art. Reference is for instance made to Curr. Opin. Immunol. 2020, 65, 97-101. Classically recognized examples of adjuvants include:

[0369] - mineral-containing compositions, including calcium salts and aluminium salts (or mixtures thereof). Calcium salts include calcium phosphate. Aluminium salts include hydroxides, phosphates, sulphates, etc., with the salts taking any suitable form (e.g. gel, crystalline, amorphous, etc.). Adsorption to these salts is preferred. The mineral containing compositions may also be formulated as a particle of metal salt. The adjuvants known as aluminium hydroxide and aluminium phosphate may be also used. The invention can use any of the "hydroxide" or "phosphate" adjuvants that are in general used as adjuvants. The adjuvants known as "aluminium hydroxide" are typically aluminium oxyhydroxide salts, which are usually at least partially crystalline. The adjuvants known as "aluminium phosphate" are typically aluminium hydroxyphosphates, often also containing a small amount of sulphate (i. e. aluminium hydroxyphosphate sulphate). They may be obtained by precipitation, and the reaction conditions and concentrations during precipitation influence the degree of substitution of phosphate for hydroxyl in the salt. Mixtures of both an aluminium hydroxide and an aluminium phosphate can be employed in the formulation according to the present invention;

[0370] - saponins, which are a heterologous group of sterol glycosides and triterpenoid glycosides that are found in the bark, leaves, stems, roots and even flowers of a wide range of plant species. Saponins from the bark of the Quillaia saponaria, Molina tree have been widely studied as adjuvants. Saponins can also be commercially obtained from Smilax ornata (sarsaprilla), Gypsophilla paniculata (brides veil), and Saponaria oficianalis (soap root). Saponin adjuvant formulations include purified formulations, such as QS21, as well as lipid formulations, such as ISCOMs. Saponin compositions have been purified using HPLC and RP-HPLC. Specific purified fractions using these techniques have been identified, including QS7, QS 17, QS 18, QS2 1, QH-A, QH-B and QH-C. Saponin formulations may also comprise a sterol, such as cholesterol. Combinations of saponins and cholesterols can be used to form unique particles called immunostimulating complexes (ISCOMs). ISCOMs generally include a phospholipid such as phosphatidylethanolamine or phosphatidylcholine. Any known saponin can be used in ISCOMs. Preferably, the ISCOM includes one or more of QuilA, QHA & QHC;

[0371] - microparticles (i.e. a particle of 100 nm to 150 pm in diameter, more preferably 200 nm to 30 pm in diameter, or 500 nm to 10 pm in diameter) formed from materials that are biodegradable and non-toxic. Such non-toxic and biodegradable materials include, but are not restricted to poly(a-hydroxy acid), polyhydroxybutyric acid, polyorthoester, polyanhydride, polycaprolactone;

[0372] - CD Id ligands, such as an a-glycosylceramide, phytosphingosine-containing a- glycosylceramides, OCH (sphingosine-truncated a-GalCer analog), KRN7000 [(2S,3S,4R)-1- O-(a-D-galactopyranosyl)-2-(A-hexacosanoylamino)-l,3,4-octadecanetriol], CRONY- 101 (3 " -sulfo-galactosyl -ceramide);

[0373] - immunostimulatory oligonucleotides, such CpG motif containing ones (a dinucleotide sequence containing an unmethylated cytosine residue linked by a phosphate bond to a guanosine residue), or Cpl motif containing ones (a dinucleotide sequence containing cytosine linked to inosine), or a double-stranded RNA, or an oligonucleotide containing a palindromic sequence, or an oligonucleotide containing a poly(dG) sequence. Immunostimulatory oligonucleotides can include nucleotide modifications / analogs such as phosphorothioate modifications and can be double-stranded or (except for RNA) single-stranded;

[0374] - compounds containing lipids linked to a phosphate-containing acyclic backbone, such as the TLR4 antagonist E5564;

[0375] - oil emulsions (e.g. Freund's adjuvant), in particular for diagnostic uses.

[0376] In particular, such adjuvants may be chosen from aluminium salts (aluminium hydroxide, aluminium phosphate), oil-in-water emulsion formulations with or without specific stimulating agents such as TLR agonists, muramyl peptides, saponin adjuvants, cytokines, detoxified mutants of bacterial toxins such as the cholera toxin, the pertussis toxin, or the E. coli heat labile toxin (LT), in particular a double mutant of the later known as dmLT (mSphere 2018, 3(4), e00215-18).

[0377] The immunogenic composition of the invention may be administered with other immunogens or immunoregulatory agents, for example, immunoglobulins, cytokines, lymphokines and chemokines. Immunogenic compositions are preferably in aqueous form, particularly at the point of administration, but they can also be presented in non-aqueous liquid forms or in dried forms e.g. as gelatin capsules, or as lyophilisates, etc.

[0378] Immunogenic compositions may include one or more preservatives, such as thiomersal or 2 -phenoxy ethanol. Mercury-free compositions are preferred, and preservative-free vaccines can be prepared.

[0379] Immunogenic compositions may include a physiological salt, such as a sodium salt e.g. to control tonicity. Sodium chloride (NaCl) is typical and may be present at between 1 and 20 mg / mL. Other salts that may be present include potassium chloride, potassium dihydrogen phosphate, disodium phosphate dehydrate, magnesium chloride, calcium chloride, etc.

[0380] Immunogenic compositions can have an osmolality of between 200 mOsm / kg and 400 mOsm / kg.

[0381] Immunogenic compositions may include compounds (with or without an insoluble metal salt) in plain water (e.g. w.f.i.) but will usually include one or more buffers. Typical buffers include: a phosphate buffer; a Tris buffer; a borate buffer; a succinate buffer; a histidine buffer (particularly with an aluminium hydroxide adjuvant); or a citrate buffer. Buffer salts will typically be included in the 5-20 mM range.

[0382] Immunogenic compositions typically have a pH between 5.0 and 9.5 e.g. between 6.0 and 8.0.

[0383] Immunogenic compositions are preferably sterile and gluten free.

[0384] Typically, the immunogenic compositions are prepared as injectables either as liquid solutions or suspensions; or as solid forms suitable for solution or suspension in a liquid vehicle prior to inj ection. The preparation may be emulsified or encapsulated in liposomes for enhanced adjuvant effect. In this respect, reference could be made to International Application WO 2010 / 136947.

[0385] Once formulated, the immunogenic compositions may be administered parenterally, by injection, either subcutaneous, intramuscular or intradermal.

[0386] Typically, the immunogenic compositions of the invention may be administered intramuscularly, e.g. by intramuscular administration to the high or the upper arm. Alternative formulations suitable for other mode of administration include oral and intranasal formulations.

[0387] In another aspect, the invention concerns a conjugate or an immunogenic composition as defined above for use in vaccination.

[0388] Protection and deprotection techniques (i.e. protecting group introduction and cleavage) are for instance described by P. G. M. Wuts and T. W. Greene (Greene's Protective Groups in Organic Synthesis, Fourth Edition,' Wiley-Interscience, 2006; or Greene's Protective Groups in Organic Synthesis, fifth Edition,' Wiley-Interscience, 2014, by P. Wuts, DOI: 10.1002 / 9781118905074). Reference is also made to “Recent Advances Toward Robust N- Protecting Groups for Glucosamine as Required for Glycosylation Strategies”, Mohamed Ramadan El Sayed Aly and El Sayed H. El Ashry, Advances in Carbohydrate Chemistry and Biochemistry, Volume 73, p. 117-224 (2016).

[0389] Definitions

[0390] The following terms and expressions contained herein are defined as follows:

[0391] As used herein, the term “alkyl” refers to a straight-chain, or branched alkyl group having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isoamyl, neopentyl, 1 -ethylpropyl, 3 -methylpentyl, 2,2-dimethylbutyl, 2,3- dimethylbutyl, hexyl, etc. The alkyl moiety of alkyl -containing groups, such as aralkyl or O- alkyl groups, has the same meaning as alkyl defined above. Lower alkyl groups, which are preferred, are alkyl groups as defined above which contain 1 to 4 carbons. A designation such as “C1-C4 alkyl” refers to an alkyl radical containing from 1 to 4 carbon atoms.

[0392] As used herein, the term “aryl” refers to a substituted or unsubstituted, mono- or bicyclic hydrocarbon aromatic ring system having 6 to 10 ring carbon atoms. Examples include phenyl and naphthyl. Preferred aryl groups include unsubstituted or substituted phenyl and naphthyl groups. Included within the definition of “aryl” are fused ring systems, including, for example, ring systems in which an aromatic ring is fused to a cycloalkyl ring. Examples of such fused ring systems include, for example, indane, indene, and tetrahydronaphthalene.

[0393] As used herein, the term “heteroaryl” refers to an aromatic group containing 5 to 10 ring carbon atoms in which one or more ring carbon atoms are replaced by at least one hetero atom such as -O-, -N-, or -S-. Examples of heteroaryl groups include pyrrolyl, furanyl, thienyl, pirazolyl, imidazolyl, thiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxathiolyl, oxadiazolyl, triazolyl, oxatriazolyl, furazanyl, tetrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, indolyl, isoindolyl, indazolyl, benzofuranyl, isobenzofuranyl, purinyl, quinazolinyl, quinolyl, isoquinolyl, benzoimidazolyl, benzothiazolyl, benzothiophenyl, thianaphthenyl, benzoxazolyl, benzisoxazolyl, cinnolinyl, phthalazinyl, naphthyridinyl, and quinoxalinyl. Included within the definition of “heteroaryl” are fused ring systems, including, for example, ring systems in which an aromatic ring is fused to a heterocycloalkyl ring. Examples of such fused ring systems include, for example, phthalimide, indoline, isoindoline, tetrahydroisoquinoline, chroman, isochroman, chromene, and isochromene. As used herein, the term “pharmaceutically acceptable” refers to those compounds, materials, compositions, and / or dosage forms which are, within the scope of sound medical judgment, suitable for contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem complications commensurate with a reasonable benefit / risk ratio.

[0394] In another aspect, the present invention is directed to pharmaceutically acceptable salts of the compounds described above. As used herein, “pharmaceutically acceptable salts” includes salts of compounds of the present invention derived from the combination of such compounds with non-toxic acid.

[0395] Acid addition salts include inorganic acids such as hydrochloric, hydrobromic, hydroiodic, sulfuric, nitric and phosphoric acid, as well as organic acids such as acetic, citric, propionic, tartaric, glutamic, salicylic, oxalic, methanesulfonic, / % / ra-toluenesulfonic, succinic, and benzoic acid, and related inorganic and organic acids.

[0396] In addition to pharmaceutically acceptable salts, other salts are included in the invention. They may serve as intermediates in the purification of the compounds, in the preparation of other salts, or in the identification and characterization of the compounds or intermediates.

[0397] The pharmaceutically acceptable salts of compounds of the present invention can also exist as various solvates, such as with water, methanol, ethanol, dimethylformamide, ethyl acetate and the like. Mixtures of such solvates can also be prepared. The source of such solvate can be from the solvent of crystallization, inherent in the solvent of preparation or crystallization, or adventitious to such solvent. Such solvates are within the scope of the present invention.

[0398] It is well known in the art how to prepare and isolate such optically active forms. Specific stereoisomers can be prepared by stereospecific synthesis using enantiomerically pure or enantiomerically enriched starting materials. The specific stereoisomers of either starting materials or products can be resolved and recovered by techniques known in the art, such as resolution of racemic forms, normal, reverse-phase, and chiral chromatography, recrystallization, enzymatic resolution, or fractional recrystallization of addition salts formed by reagents used for that purpose. Useful methods of resolving and recovering specific stereoisomers described in Eliel, E. L.; Wilen, S.H. Stereochemistry of Organic Compounds,' Wiley: New York, 1994, and Jacques, J, et al. Enantiomers, Racemates, and Resolutions,' Wiley: New York, 1981, each incorporated by reference herein in their entireties.

[0399] As used herein, the term “oligosaccharide” more particularly refers to a saccharide containing from 2 to 10 monosaccharides (simple sugars). As used herein, the term “polysaccharide” more particularly refers to a saccharide containing more than 10 monosaccharides (simple sugars).

[0400] As used herein, a range of values in the form “x-y” or “x to y”, or “x through y”, include integers x, y, and the integers there between. For example, the phrases “1-6”, or “1 to 6” or “1 through 6” are intended to include the integers 1, 2, 3, 4, 5, and 6. Preferred embodiments include each individual integer in the range, as well as any subcombination of integers. For example, preferred integers for “1-6” can include 1, 2, 3, 4, 5, 6, 1-2, 1-3, 1-4, 1-5, 2-3, 2-4, 2- 5, 2-6, etc.

[0401] As used herein, the term “donor” more particularly refers to a mono-, oligo- or polysaccharide bearing a leaving group at the anomeric position.

[0402] As used herein, the term “acceptor” more particularly refers to a mono-, oligo- or polysaccharide having at least a free hydroxyl group, in general other than the anomeric hydroxyl, preferably at least the free hydroxyl group corresponding to the elongation site of the growing chain.

[0403] By “divalent C1-C12 alkyl, C2-C12 alkenyl or C2-C12 alkynyl chain” is in particular meant a C1-C12 alkane diyl, C2-C12 alkene diyl or C2-C12 alkyne diyl chain, respectively.

[0404] FIGURES

[0405] Figure 1 displays data from immunization assays according to example 20, with:

[0406] NEW 1 - SFlb-TT - [ABACC(E)D]I6-TT

[0407] NEW 2 - (SFlb)2-TT - [(ABACC(E)D)2]21.5-TT

[0408] NEW 3 - (SFlb)3-TT - [(ABACC(E)D)3]23.5-TT

[0409] Wherein TT is tetanus toxoid.

[0410] Figure 2 displays data from immunization assays according to example 20, with:

[0411] NEW 6 - SF2aSFlb-TT - [(AB(E)CD)(ABACC(E)D)]2I-TT

[0412] NEW 7 - SF3aSFlb-TT - [((E)ABACCD)(ABACC(E)D)]I9-TT

[0413] NEW 8 - SF3aSF2a-TT - [((E)ABACCD)(AB(E)CD)]I8 5-TT

[0414] NEW 9 - SF3a(SF2a)2-TT - [((E)ABACCD)(AB(E)CD)2]25-TT

[0415] Wherein TT is tetanus toxoid.

[0416] Figure 3 displays data from immunization assays according to example 20, with: NEW 17 - (SF2a)2SFlb-TT [(AB(E)CD)2(ABACC(E)D)]2I-TT

[0417] NEW 18 - (SF3a)2SFlb-TT [((E)ABACCD)2(ABACC(E)D)]2I.5-TT

[0418] NEW 19 - (SF2a)2(SFlb)2-TT [(AB(E)CD)2(ABACC(E)D)2]20-TT

[0419] NEW 20 - (SF2a)2(SF3a)2-TT [(AB(E)CD)2((E)ABACCD)2]22-TT

[0420] NEW 21 - (SF3a)2(SF2a)2-TT [((E)ABACCD)2(AB(E)CD)2]28-TT

[0421] Wherein TT is tetanus toxoid.

[0422] EXAMPLES

[0423] Example 1: Synthesis of donor A

[0424] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-«-L-rhamnopyranoside (2). To a solution of diol 1 (5 g, 16.9 mmol, 1.0 equiv.) in anhydrous DCM (170 mL) stirred at -20 °C under Ar, were added 2,6-lutidine (4.0 mL, 34 mmol, 2.0 equiv.) and TBSOTf (5.8 mL, 25.5 mmol, 1.5 equiv.). The mixture was stirred from -20 °C to 0 °C for 1.5 h. Then, MeOH was added and the mixture was stirred for 15 min and a precipitate appeared. The suspension was filtered through a pad of Celite, washed with a generous amount of MeOH and the filtrate was concentrated under reduced pressure. The crude product was purified by flash chromatography (cHex / EtOAc 95:5 to 8:2) to give the desired alcohol 2 (6.5 g, 93%) as a yellow oil. 'H NMR (400 MHz, CDC13) 5 (ppm): 7.36-7.29 (m, 5H, Ctf-Ar), 5.94-5.86 (m, 1H, H-2AII), 5.29 (ddd, J = 17.1, 3.7, 1.6 Hz, 1H, H-3aAn), 5.20 (ddd, J = 10.4, 3.2, 1.2 Hz, 1H, H-3bAn), 4.86 (d, J= 11.2 Hz, 1H, CT / HPh), 4.85 (d, Ji,2= 1.4 Hz, 1H, H-l), 4.61 (d, J= 11.1 Hz, 1H, CHflPh), 4.18 (ddt, J = 13.2, 5.1, 1.6 Hz, 1H, H-laAii), 4.04 (dd, J = 9.0, 3.5 Hz, 1H, H-3), 4.00 (ddt, J= 13.2, 6.1, 1.4 Hz, 1H, H-lbAii), 3.84 (dd, J= 3.6, 1.5 Hz, 1H, H-2), 3.78-3.75 (m, 1H, H-5), 3.37 (t, J= 9.3 Hz, 1H, H-4), 2.64 (br s, 1H, OH), 1.29 (d, J= 6.4 Hz, 3H, H-6), 0.97 (s, 9H, C(CH3)3), 0.16 (s, 3H, C#3Si), 0.15 (s, 3H, C#3Si). HRMS(ESI-TOF): m / z [M+NH4]+calcd for C22H4o05SiN 426.2662; found 426.2670.

[0425] Allyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranoside (3). Alcohol 2 (3.0 g, 7.3 mmol, 1.0 equiv.) was dissolved in anhydrous DCM (152 mL). Levulinic acid (1.35 mL, 13.2 mmol, 1.8 equiv.), DCC (2.3 g, 11.0 mmol, 1.5 equiv.) and DMAP (1.8 g, 14.7 mmol, 2.0 equiv.) were added to the solution and the mixture was stirred at rt for 1 h under Ar. Then, the reaction mixture was filtered through a pad of Celite and the filtrate was concentrated under reduced pressure. The obtained residue was dissolved in DCM (100 mL), and washed with 5% aq. NaHCO3(50 mL) and brine (50 mL). The combined organic phases were dried over anhydrous Na2SO4. The solution was evaporated under pressure. The crude was dissolved in EtOAc (200 mL) and the mixture was stored at 4 °C. After 15 h, the solution was filtered over a pad of Celite and the filtrate was concentrated to dryness under vacuo. The residue was purified by flash chromatography (TolZEtOAc 9:1 to 75:25) to give compound 3 (3.5 g, 96%) as a yellow oil. 'H NMR (400 MHz, CDC13) 5 (ppm): 7.38-7.30 (m, 5H, Ctf-Ar), 5.94-5.84 (m, 1H, H-2AII), 5.28 (ddd, J = 17.2, 3.7, 1.6 Hz, 1H, H-3aAn), 5.19 (ddd, J= 10.4, 3.3, 1.2 Hz, 1H, H-3bAn), 5.09 (dd, J= 3.7, 1.8 Hz, 1H, H-2), 4.91 (d, J= 11.2 Hz, 1H, C / ZHPh), 4.70 (d, Ji,2= 1.6 Hz, 1H, H-l), 4.62 (d, J= 11.1 Hz, 1H, CHflPh), 4.18^4.12 (m, 2H, H-la^i, H-3), 3.96 (ddt, J= 13.1, 5.9, 1.4 Hz, 1H, H-lbAn), 3.78-3.72 (m, 1H, H-5), 3.36 (t, J= 92 Hz, 1H, H-4), 2.80-2.68 (m, 4H, 2 x (CH)2Lev), 2.22 (s, 3H, (C#3Lev)), 1.29 (d, J= 6.5 Hz, 3H, H- 6), 0.92 (s, 9H, C(C#3)3), 0.11 (s, 3H, C / CSi), 0.12 (s, 3H, C / CSi). HRMS(ESI-TOF): m / z [M+NH4]+calcd for C27H46O7SiN 524.3038; found 524.3031.

[0426] 4-t?-Benzyl-3-t?- / c / 7-butyldiniethylsilyl-2-t?-leMilinoyl-6< / / / -l -rh:iin nopyranose (4). To a solution of compound 3 (11 g, 21.6 mmol, 1.0 equiv.) in DCM / H2O (3: 1, 216 mL), stirred at rt, was added PdCl2(60%, 255 mg, 0.86 mmol, 0.04 equiv.). The mixture was stirred for 4 h at 50 °C. Then, a solution of I2 (11 g, 43.2 mmol, 2.0 equiv.) and NaHCO3(14.5 g, 172.8 mmol, 8.0 equiv.) in THF / H2O (5: 1, 238 mL) was poured at 0 °C and the mixture was stirred for another 3 h at rt. 10% aq. Na2S2O3(20 mL) was added. The suspension was filtered over a pad of Celite and cotton. THF was removed under reduced pressure and DCM (100 mL) was added. The aqueous layer was extracted with DCM (2 x 50 mL) and the combined organic phases were washed with satd aq. NaHCO3(80 mL) and brine (80 mL), dried over anhydrous Na2SO4and concentrated to dryness under vacuo. The residue was filtered through a pad of silica (Tol / EtOAc 9: 1 to 7:3) to give the desired hemiacetal 4 (9.8 g, 97%, a / p 10:3) as a yellow oil. 'H NMR (400 MHz, CDC13) 5 (ppm): 7.38-7.30 (m, 5H, Ctf-Ar), 5.94-5.84 (m, 1H, H-2An), 5.28 (ddd, J = 17.2, 3.7, 1.6 Hz, 1H, H-3aAn), 5.19 (ddd, J = 10.4, 3.3, 1.2 Hz, 1H, H-3bAn), 5.09 (dd, J = 3.7, 1.8 Hz, 1H, H-2), 4.91 (d, J= 11.2 Hz, 1H, CZ / HPh), 4.70 (d, Ji,2= 1.6 Hz, 1H, H-l), 4.62 (d, J= 11.1 Hz, 1H, CHflPh), 4.18^4.12 (m, 2H, H-laAn, H-3), 3.96 (ddt, J = 13.1, 5.9, 1.4 Hz, lH, H-lbAii), 3.78-3.72 (m, 1H, H-5), 3.36 (t, J= 9.2 Hz, 1H, H-4), 2.80-2.68 (m, 4H, 2 x CZf2Lev), 2.22 (s, 3H, C#3Lev), 1.29 (d, J= 6.5 Hz, 3H, H-6), 0.92 (s, 9H, C(C#3)3), 0.12 (s, 3H, C#3Si), 0.11 (s, 3H, C / fiSi).

[0427] 4-t?-Benzyl-3-t?- / c / 7-butyldiniethylsilyl-2-t?-leMilinoyl-6< / / / -l -rh:ininopyr:inosyl trichloroacetamidate (A). To a solution of hemiacetal (22.2 g, 47.8 mmol, 1.0 equiv.) in anhydrous DCE (248 mL), stirred at rt under Ar, were successively added C13CCN (19.2 mL, 191 mmol, 4.0 equiv.) and K2CO3 (19.8 mg, 143 mmol, 3.0 equiv.). The mixture was stirred for 3 h at rt. Salts were filtered off over a pad of Celite and the filtrate was concentrated under reduced pressure. The residue was purified by flash chromatography (Tol / EtOAc 9: 1 to 75:25 + 1% Et3N) to give A (27 g, 92%, a / 0 95:5) as a yellow solid. 'H NMR (400 MHz, CDCI3) 5 (ppm): 8.66 (s, 1H, NH), 7.37-7.30 (m, 5H, Ctf-Ar), 6.14 (d, Ji,2= 1.9 Hz, 1H, H-l), 5.25 (dd, J= 3.4, 2.1 Hz, 1H, H-2), 4.93 (d, J= 11.0 Hz, 1H, CZ / HPh), 4.64 (d, J= 11.2 Hz, 1H, CHflPh), 4.22 (dd, J = 9.0, 3.4 Hz, 1H, H-3), 3.97-3.90 (m, 1H, H-5), 3.47 (t, J= 9.4 Hz, 1H, H-4), 2.82-2.74 (m, 4H, 2 x CH2L^ 2.23 1.32 (d, J= 6.1 Hz, 3H, H-6), 0.92 (s, 9H,

[0428] C(C#3)3), 0.13 (s, 3H, CTLSi), 0.12 (s, 3H, C / / 3Si).

[0429] Example 2: Synthesis of disaccharide acceptor BC

[0430] Allyl 3,4-di-O-benzyl-2-CMevulinoyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranoside (10). To a solution of acceptor C (9.4 g, 22.4 mmol, 1.25 equiv.) in anhydrous Toluene (112 mL), stirred under Ar, were successively added 3,4-di-(9-benzyl-2-(9-levulinoyl-a-L-rhamnopyranosyl trichloroacetimidate (donor B, 10.4 g, 17.8 mmol, 1.0 equiv.) and activated 4A MS (4.6 g). The suspension was stirred for 25 min at rt then cooled to - 20 °C and stirred for another 5 min. TMSOTf (966 pL, 5.3 mmol, 0.3 equiv.) was slowly added at this temperature. The mixture was then stirred for 1 h at - 20°C under Ar. EtsN (868 pL, 6.23 mmol, 0.35 equiv.) was added. Tthe suspension was filtered over a pad of Celite. The filtrate was concentrated under reduced pressure and purified by flash chromatography (Tol / EtOAc 95:5 to 75:25) to give the desired disaccharide 10 (15 g, quant.) as a yellow oil. 'H NMR (400 MHz, CDC13) 5 (ppm): 7.89-7.82 (m, 4H, C / f-Ar), 7.52-7.46 (m, 3H, C77-Ar), 7.38-7.25 (m, 10H, C / f-Ar), 5.94-5.85 (m, 1H, H-2AII), 5.44 (dd, J= 3.4, 1.8 Hz, 1H, H-2B), 5.30 (ddd, J = 17.4, 3.7, 1.4 Hz, 1H, H-3aAn), 5.25-5.21 (m, 2H, H-2C, H- 3bAn), 5.09 (d, Ji,2 = 1.8 Hz, 1H, H-1B), 4.97 (d, J= 11.1 Hz, 1H, CZ / HPh), 4.92 (d, J= 11.1 Hz, 1H, CHTTPh), 4.81 (d, Ji,2= 1.6 Hz, 1H, H-1C), 4.76 (d, J = 11.3 Hz, 1H, C / ZHPh), 4.66 (d, J = 11.3 Hz, 1H, C / THPh), 4.58 (d, J = 11.6 Hz, 1H, C / ZHPh), 4.46 (d, J = 11.5 Hz, 1H, C / THPh), 4.25 (dd, J = 9.5, 3.1 Hz, 1H, H-3C), 4.16 (ddt, J= 13.0, 5.8, 1.5 Hz, 1H, H-laAn), 4.12 (s, 2H, CH2CA), 4.00 (ddt, J= 13.0, 6.1, 1.1 Hz, 1H, H-lbAn), 3.89 (dd, J= 9.4, 3.3 Hz, 1H, H-3B), 3.85-3.75 (m, 2H, H-5B,H-5C), 3.52 (t, J= 10.2 Hz, 1H, H-4C), 3.42 (t, J= 10.2 Hz,

[0431] IH, H-4B), 2.64-2.55 (m, 4H, 2 x (CH)2Lev\ 2.11 (s, 3H, (C#3Lev)), 1.33 (d, J= 6.3 Hz, 3H, H-6C), 1.30 (d, J= 6.2 Hz, 3H, H-6B).

[0432] Allyl 3,4-di-t?-benzyl-«-L-rhamnopyranosyl-( 1 — >3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-«-L-rhamnopyranoside (acceptor BC). To a solution of compound 10 (15.9 g, 18.8 mmol, 1.0 equiv.) in anhydrous Py (256 mL) and AcOH (188 mL), stirred at rt under Ar, was added hydrazine monohydrate (50-60%, 2.3 mL, 26.3 mmol, 1.4 equiv.). The suspension was stirred for 15 min at 0 °C then for 1 h at rt under Ar. Following addition of water (200 mL) and DCM (200 mL), the two layers were separated and the aq. one was extracted twice with DCM (50 mL). The combined organic phases were washed with 5% aq. citric acid (150 mL) and brine (150 mL), dried over Na2SO4 and concentrated to dryness. The crude was directly purified by flash chromatography (Tol / EtOAc 95:5 to 85: 15) to give the desired acceptor BC (12 g, 85%) as a translucent oil. 'H NMR (400 MHz, CDCI3) 5 (ppm): 7.87-7.79 (m, 4H, Ctf-Ar), 7.53-7.43 (m, 3H, Ctf-Ar), 7.37-7. 18 (m, 10H, Ctf-Ar), 5.95-5.85 (m, 1H, H-2An), 5.31 (ddd, J= 17.2, 3.6, 1.5 Hz, 1H, H-3aAn), 5.25-5.22 (m, 2H, H- 2C, H-3bAn ), 5.13 (d, Ji,2= 1.5 Hz, 1H, H-1B), 4.89 (d, J= 11.2 Hz, 1H, C / ZHPh), 4.86 (d, J=

[0433] I I.2 Hz, 1H, CHflPh), 4.82 (d, J\,2= 1.8 Hz, 1H, H-1C), 4.78 (d, J = 11.3 Hz, 1H, CffHPh), 4.67 (d, J = 11.1 Hz, 1H, C / THPh), 4.58 (d, J= 11.6 Hz, 1H, CZ / HPh), 4.50 (d, J= 11.6 Hz, 1H, C / THPh), 4.22 (dd, J= 9.5, 3.4 Hz, 1H, H-3C), 4.18 (ddt, J= 12.5, 5.1, 1.3 Hz, 1H, H- laAn), 4.14 (s, 2H, CH2CA), 4.00 (ddt, J= 12.7, 6.0, 1.3 Hz, 1H, H-lbAn), 3.92 (dd, J= 3.2, 1.7 Hz, 1H, H-2B), 3.86-3.79 (m, 1H, H-5C), 3.78-3.79 (m, 2H, H-3B, H-5B), 3.51 (t, J= 9.6 Hz, 1H, H-4C), 3.46 (t, J= 9.3 Hz, 1H, H-4B), 1.34 (d, J= 6.2 Hz, 3H, H-6C), 1.29 (d, J= 6.1 Hz, 3H, H-6B).

[0434] Example 3: Synthesis of trisaccharide donor ABC

[0435]

[0436] Allyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl- ( 1 — >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1 — >3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-«-L-rhamnopyranoside (11). Acceptor BC (702 mg, 0.939 mmol, 1.0 equiv.) and A (689 mg, 1.13 mmol, 1.2 equiv.) were dissolved in anhydrous Toluene (9.4 mL) and activated 4A MS (1.4 g) was added. The suspension was stirred under Ar for 25 min at rt, then cooled to —30 °C and stirred for another 5 min. TMSOTf (9 pL, 0.05 mmol, 0.05 equiv.) was slowly added at this temperature. The mixture was then stirred for 1 h at —30 °C under Ar. After that time, the mixture was neutralized by slow addition of EtsN (8 pL, 0.06 mmol, 0.05 equiv.) and the suspension was filtered over a pad of Celite. The filtrate was concentrated under reduced pressure and purified by flash chromatography (cHex / EtOAc 90: 10 to 75:25) to give the desired trisaccharide 11 (1 g, 91%) as a crystalline solid.JH NMR (400 MHz, CDCh) 5 (ppm): 7.86-7.75 (m, 4H, Ctf-Ar), 7.52-7.42 (m, 3H, Ctf-Ar), 7.38—7. 18 (m, 15H, Ctf-Ar), 5.94-5.84 (m, 1H, H-2AII), 5.29 (ddd, J= 17.2, 3.7, 1.7 Hz, 1H, H-3aAn), 5.25-5.20 (m, 3H, H-2A, H-2C, H-3bAii), 5.06 (d, Jyi = 1.8 Hz, 1H, H-1B), 4.90-4.87 (m, 4H, H-1A, C / ZHPh), 4.81 (d, J = 1.6 Hz, 1H, H-1C), 4.67-4.51 (m, 5H, H-1C, C / ZHPh), 4.19^4.13 (m, 5H, H-3C, H-3A, H-laAii, C#2CA), 4.00 (ddt, J= 12.8, 6.0, 1.2 Hz, 1H, H-lbAn), 3.97 (t, J= 2.5 Hz, 1H, H-2B), 3.85-3.75 (m, 3H, H-5A, H-3B, H-5C), 3.70-3.63 (m, 1H, H-5B), 3.47 (t, J= 9.4 Hz, 1H, H-4C), 3.46 (t, J= 9.4 Hz, 1H, H-4B), 3.34 (t, J= 9.4 Hz, 1H, H-4A), 2.77^2.67 (m, 4H, 2 X CZf2Lev), 2.21 (s, 3H, CZf3Lev), 1.24 (d, J= 5.5 Hz, 6H, H-6C, H-6B), 1.16 (d, J= 6.2 Hz, 3H, H-6A), 0.92 (s, 9H, C(CH3)3), 0.14 (s, 3H, C#3Si), 0.11 (s, 3H, CftSi). HRMS (ESI-TOF): m / z [M+NH4]+calcd for CeeH^ClOieSiN 1212.5460; found 1212.5477. 4-O-Benzyl-3-O-terCbutyldimethylsilyl-2-O-levulinoyl-«-L-rhamnopyranosyl-( 1— >2)-3,4- di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl)-a7?- L-rhamnopyranose (12). To a solution of compound 11 (7.0 g, 5.88 mmol, 1.0 equiv.) in DCM / H2O (3: 1, 58 mL) stirred at rt, was added PdCh (60%, 122 mg, 0.41 mmol, 0.07 equiv.). The mixture was stirred for 5 h at 50 °C. Then, a solution of NIS (1.6 g, 7.06 mmol, 1.2 equiv.) in THF / H2O (4: 1, 39 mL) was poured at 0 °C and the mixture was stirred for another 3 h from 0 °C to rt. After that time, 10% aq. Na2S2O3 (35 mL) was added, the suspension was filtered over a pad of Celite and cotton. THF and DCM were removed under reduced pressure and EtOAc (100 mL) was added. The aqueous layer was extracted with EtOAc (2 x 20 mL) and the combined organic phases were washed with satd aq. NaHCCL (100 mL) and brine (100 mL), dried over anhydrous Na2SO4 and concentrated to dryness under vacuo. The residue was purified by flash chromatography (Tol / EtOAc 9:1 to 75:25) to give hemiacetal 12 (5.6 g, 83%, a / p 10:1.5) %as a brown oil.1H NMR (400 MHz, CDCI3) 5 (ppm): 7.86-7.75 (m, 4H, Ctf-Ar), 7.51 —7.42 (m, 3H, Ctf-Ar), 7.38— 7. 15 (m, 15H, Ctf-Ar), 5.25-5.23 (m, 2H, H-2A, H-2C), 5.18 (d, Ji,2 = L6 Hz, 1H, H-1C), 5.07 (d, Ji,2= 1.7 Hz, 1H, H-1B), 4.91-4.87 (m, 4H, H-1A, C / ZHPh), 4.67-4.51 (m, 5H, C / ZHPh), 4.22 (dd, J= 9.4, 3.3 Hz, 1H, H-3C), 4.16 (dd, J= 9.1, 3.3 Hz, 1H, H-3A), 4.12 (s, 2H, CH2CA), 4.03-3.96 (m, 2H, H-5C, H-2B), 3.83-3.79 (m, 2H, H-3B, H-5A), 3.71 —3.64 (m, 1H, H-5B), 3.47 (t, J= 9.4 Hz, 1H, H-4C), 3.46 (t, J= 9.4 Hz, 1H, H-4B), 3.34 (t, J= 9.4 Hz, 1H, H-4A), 2.77^2.67 (m, 4H, 2 x CH2Lev), 2.21 (s, 3H, C / CK-V), 1.24 (d, J= 6.5 Hz, 3H, H-6B), 1.22 (d, J= 6.5 Hz, 3H, H-6C), 1.15 (d, J= 6.4 Hz, 3H, H-6A), 0.93 (s, 9H, C(CZ73)3), 0.14 (s, 3H, C#3Si), 0.11 (s, 3H, C / ASi). HRMS (ESI-TOF): m / z [M+NH4]+calcd for CesHssClOieSiN 1172.5164; found 1172.5157.

[0437] 4-O-Benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl-( 1— >2)-3,4- di-f?-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl)-a7?- L-rhamnopyranosyl (A-phenyl)trifluoroacetimidate (Donor ABC). To a solution of hemiacetal 12 (5.6 g, 4.88 mmol, 1.0 equiv.) in anhydrous acetone (98 mL) stirred at rt under Ar, were successively added PTFAC1 (1.2 mL, 7.33 mmol, 1.5 equiv.) and K2CO3 (1.3 g, 9.77 mmol, 2.0 equiv.). The mixture was stirred for 1 h at rt. After that time, the reaction mixture was filtered over a pad of Celite to remove salts and the filtrate was concentrated to dryness under vacuo. The residue was quickly purified in a fritted funnel (Tol / EtOAc 9: 1 to 7:3 + 1% TEA) to give the desired donor ABC (6.4 g, 98%, a / p 10:2) as a yellow solid. 'H NMR (400 MHz, CDCI3) 5 (ppm): 7.86-7.76 (m, 4H, Ctf-Ar), 7.52-7.43 (m, 3H, Ctf-Ar), 7.38—7.1 1 (m, 18H, Ctf-Ar), 6.85-6.83 (m, 2H, Ctf-Ar), 6.17 (br s, 1H, H-1C), 5.39 (t, J= 2.3 Hz, 1H, H- 2C), 5.27 (dd, J= 3.3, 2.0 Hz, 1H, H-2A), 5.11 (d, Ji,2= 1.4 Hz, 1H, H-1B), 4.93-4.88 (m, 4H, H-1A, C / ZHPh), 4.69-4.55 (m, 5H, C / ZHPh), 4.22 (dd, J= 9.6, 3.0 Hz, 1H, H-3C), 4.17 (dd, J = 9.3, 3.3 Hz, 1H, H-3A), 4.12 (s, 2H, C#2CA), 3.98 (t, J= 2.4 Hz, 1H, H-2B), 3.94-3.77 (m, 3H, H-5C, H-5A, H-2B), 3.72-3.56 (m, 1H, H-5B), 3.56 (t, J= 9.6 Hz, 1H, H-4C), 3.48 (t, J= 9.3 Hz, 1H, H-4B), 3.35 (t, J= 9.3 Hz, 1H, H-4A), 2.78-2.69 (m, 4H, 2 x C#2Lev), 2.21 (s, 3H, CZZsLev), 1.28 (d, J= 6.3 Hz, 3H, H-6B), 1.26 (d, J= 6.2 Hz, 3H, H-6C), 1.15 (d, J= 6.2 Hz, 3H, H-6A), 0.94 ( 0.15 (s, 3H, CT / iSi), 0.12 (s, 3H, CT / iSi).

[0438] Example 4: Synthesis of tetrasaccharide ABCD

[0439] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl- ( 1 — >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1 — >3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (ABCD). To a solution of donor ABC (6.4 g, 4.8 mmol, 1.0 equiv.) in anhydrous toluene / DCM (3:1, 96 mL), stirred at rt under Ar, were successively added 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (D, 2.6 g, 5.7 mmol, 1.2 equiv.) and activated 4A MS (1.3 g). The suspension was stirred for 15 min at rt, then cooled to —40 °C and stirred for another 10 min. TBSOTf (110 pL, 0.48 mmol, 0.1 equiv.) was slowly added at this temperature. The mixture was then stirred for 2 h from —40 °C to —20 °C under Ar. After that time, EtsN (94 pL, 0.68 mmol, 0.14 equiv.) was added, the suspension wasstirred for 10 min at —20 °C and filtered over a pad of Celite. The filtrate was concentrated under reduced pressure and purified by flash chromatography (Tol / EtOAc 95:5 to 8:2) to give the desired tetrasaccharide ABCD (6.6 g, 86%) as a whitish crystalline solid.JH NMR (400 MHz, CDC13) 5 (ppm): 7.85-7.82 (m, 3H, Ctf-Ar), 7.68 (s, 1H, Ctf-Ar), 7.52-7.45 (m, 4H, Ctf-Ar), 7.39—7. 17 (m, 19H, Ctf-Ar), 7.03 (d, J= 7.4 Hz, 1H, WTCA), 5.94-5.84 (m, 1H, H-2AII), 5.56 (s, 1H, H-7D), 5.30 (ddd, J = 17.2, 3.5, 1.5 Hz, 1H, H-3aAn), 5.25-5.21 (m, 3H, H-2C, H-2A, H-3bAn), 5.09 (d, Ji,2= 8.3 Hz, 1H, H-1D), 5.05 (d, Ji,2= 1.7 Hz, 1H, H-1B), 4.93 (d, Ji,2= 1.9 Hz, 1H, H-1A), 4.90-4.87 (m, 3H, C / ZHPh, H-1C), 4.81 (d, J= 11.5 Hz, 1H, C / ZHPh), 4.65-4.52 (m, 6H, H-3D, C / ZHPh), 4.41 -4.34 (m, 2H, H-6aD, H-laAn), 4.16 (dd, J = 9.2, 3.2 Hz, 1H, H-3A), 4.14-4.08 (m, 2H, H-3C, H-lbAn), 4.03 (s, 2H, C#2CA), 4.01 -3.96 (m, 2H, H-5C, H-2B), 3.83-3.75 (m, 3H, H-5A, H-3B, H-6bD), 3.70-3.56 (m, 3H, H-5B, H- 4D, H-5D), 3.50-3.43 (m, 2H, H-2D, H-4B), 3.33 (td, J= 9.4, 1.8 Hz, 1H, H-4C, H-4A), 2.77^2.67 (m, 4H, 2 x CH2L^ 2.21 (s, 3H, C / CK-V), 1.24 (d, J= 6.1 Hz, 3H, H-6B), 1.09 (d, J = 6.2 Hz, 3H, H-6A), 0.92 ( 0.71 (d, J= 6.1 Hz, 3H, H-6C), 0.15 (s, 3H, C#3Si),

[0440] 0.12 (s, 3H, C#3Si). HRMS (ESI-TOF): m / z [M+NH4]+calcd for CsiHioiCU^OsSi 1607.5409; found 1607.5380.

[0441] ABCD could also be obtained via the following alternative route:

[0442] 3,4-Di-O-benzyl-2-O-levulinoyl-a-L-rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-a-L-rhamnopyranose (13). To a solution of disaccharide 10 (4.7 g, 5.6 mmol, 1.0 equiv.) in DCM / H2O (3: 1, 55 mL) stirred at rt, was added PdCL (60%, 65 mg, 221 pmol, 0.04 equiv.). The mixture was stirred for 16 h at 50 °C. Then a solution of I2 (2.8 g, 11.0 mmol, 2.0 equiv.) and NaHCO3(3.71 g, 44.1 mmol, 8.0 equiv.) in THF / H2O (4: 1, 40 mL) was poured at rt and the mixture was stirred for 2 h at this temperature. After that time, the reaction mixture was filtered over a pad of Celite and rinsed with DCM (300 mL). 10% aq. Na2S2O3(100 mL) was added to the filtrate. The aqueous layer was extracted with DCM (150 mL) and the combined organic phases were washed with saturated aq. NaHCO3(100 mL) and brine (100 mL), dried by passing through a phase-separatory filter and concentrated to dryness under vacuo. The residue was purified by flash chromatography (Tol / EtOAc 85: 15 to 70:30) to give the desired compound 13 (3.2 g, 71%, a / p 10: 1) as a yellow oil. The a anomer had: 'H NMR (400 MHz, CDC13) 5 7.82 - 7.67 (m, 4H), 7.43 - 7.32 (m, 3H), 7.29 - 7.09 (m, 10H), 5.33 (dd, J= 3.3, 1.8 Hz, 1H), 5.14 (dd, J= 3.3, 1.9 Hz, 1H), 5.08 (dd, J= 3.9, 1.8 Hz, 1H), 4.99 (d, J= 1.8 Hz, 1H), 4.87 (d, J = 11.2 Hz, 1H), 4.81 (d, J = 11.1 Hz, 1H), 4.66 (d, J = 11.2 Hz, 1H), 4.55 (d, J = 11.1 Hz, 1H), 4.48 (d, J= 11.4 Hz, 1H), 4.35 (d, J= 11.5 Hz, 1H), 4.19 (dd, J = 9.5, 3.3 Hz, 1H), 4.08 - 3.99 (m, 3H), 3.92 (dq, J= 9.4, 6.2 Hz, 1H), 3.78 (dd, J= 9.3, 3.4 Hz, 1H), 3.68 (dq, J= 9.4, 6.2 Hz, 1H), 3.42 (t, J= 9.5 Hz, 1H), 3.31 (t, J= 9.4 Hz, 1H), 2.90 (d, J = 4.0 Hz, 1H), 2.59 - 2.38 (m, 4H), 1.99 (s, 3H), 1.23 - 1.17 (m, 6H).

[0443] 3,4-Di-O-benzyl-2-CMevulinoyl-a-L-rhamnopyranosyl-(l— >3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-a-L-rhamnopyranosyl trichloroacetimidate (Donor BC). To a solution of hemiacetal 13 (3.2 g, 3.9 mmol, 1.0 equiv.) in anhydrous DCM (35 mL) stirred at 0 °C under Ar, were successively added TCACN (1.2 mL, 11.7 mmol, 3.0 equiv.) and DBU (291 pL, 2.0 mmol, 0.5 equiv.). The mixture was stirred for 1 h at rt and concentrated to dryness under vacuo. The residue was purified by flash chromatography (Tol / EtOAc 95:5 to 90: 10 + 0.5% TEA) to give the desired donor BC (2.45 g, 66%) as a yellow oil. 'H NMR (400 MHz, CDCh) 8 8.63 (s, 1H), 7.82 - 7.69 (m, 4H), 7.45 - 7.34 (m, 3H), 7.33 - 7.09 (m, 10H), 6.13 (d, J= 2.0 Hz, 1H), 5.36 (dd, J = 3.3, 1.8 Hz, 1H), 5.29 (dd, J= 3.3, 2.0 Hz, 1H), 5.03 (d, J= 1.8 Hz, 1H), 4.89 (d, J= 11.1 Hz, 1H), 4.81 (d, J= 11.2 Hz, 1H), 4.69 (d, J= 11.0 Hz, 1H), 4.58 - 4.50 (m, 2H), 4.41 (d, J= 11.4 Hz, 1H), 4.23 (dd, J = 9.5, 3.3 Hz, 1H), 4.06 (d, J= 14.7 Hz, 1H), 4.02 (d, J= 14.7 Hz, 1H), 3.90 (dq, J= 9.5, 6.3 Hz, 1H), 3.78 (dd, J= 9.2, 3.3 Hz, 1H), 3.70 (dq, J = 9.4, 6.1 Hz, 1H), 3.53 (t, J= 9.6 Hz, 1H), 3.33 (t, J= 9.4 Hz, 1H), 2.59 - 2.41 (m, 4H), 2.00 (s, 3H), 1.26 (d, J = 6.2 Hz, 3H), 1.17 (d, J = 6.2 Hz, 3H).

[0444] Allyl 3,4-di-O-benzyl-a-L-rhamnopyranosyl-( 1 — >3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-a-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido-P-D-glucopyranoside (BCD). To a solution of acceptor D (262 mg, 579 pmol, 1.1 equiv.) and Donor BC (500 mg, 526 pmol, 1.0 equiv.) in anhydrous Tol / DCM (3:1, 3 mL), was added 4A MS (300 mg). The suspension was stirred at rt for 30 min under Ar and cooled to -40 °C. After 5 min, TMSOTf (29 pL, 158 pmol, 0.3 equiv.) was added. After 30 min, EtsN was added. The suspension was filtered on a fritted funnel, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (Tol / EtOAc 90:0 to 80:20) to give compound BCD (434 mg, 66%), as a white foam.1H NMR (400 MHz, CDCh) 6 7.86 - 7.78 (m, 3H), 7.72 (d, J= 1.6 Hz, 1H), 7.54 - 7.42 (m, 3H), 7.41 - 7.15 (m, 15H), 7.01 (d, J= 7.4 Hz, 1H), 5.85 (dddd, J= 16.9, 10.3, 6.4, 5.4 Hz, 1H), 5.54 (s, 1H), 5.37 (dd, J= 3.3, 1.9 Hz, 1H), 5.28 (dq, J= 17.2, 1.6 Hz, 1H), 5.24 - 5.17 (m, 2H), 5.08 - 5.01 (m, 2H), 4.89 - 4.80 (m, 3H), 4.61-4.50 (m, 2H), 4.48. - 4.41 (m, 2H), 4.40 - 4.30 (m, 3H), 4.15 (dd, J = 9.4, 3.3 Hz, 1H), 4.08 (ddt, J = 12.8, 6.4, 1.3 Hz, 1H), 4.00 - 3.90 (3, 3H), 3.84 - 3.70 (m, 3H), 3.57 - 3.33 (m, 3H), 3.33 - 3.23 (m, 2H), 2.61 - 2.48 (m, 4H), 2.07 (s, 3H), 1.26 (d, J= 6.3 Hz, 3H), 0.74 (d, J= 6.1 Hz, 3H).

[0445] Allyl 3,4-di-O-benzyl-a-L-rhamnopyranosyl-( 1 — >3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-a-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido-p-D-glucopyranoside (Acceptor BCD). To a solution of trisaccharide BCD (434 mg, 354 mmol, 1.0 equiv.) in a mixture of anhydrous pyridine (2.1 mL) and AcOH (1.4 mL) stirred at rt, was added hydrazine monohydrate (50-60%, 35 pL, 708 mmol, 2.0 equiv.). The suspension was stirred for 1 h at rt. Following addition of EtOAc (50 mL), the organic solution was washed several times with aqueous CuSCU, water, saturated aqueous NaHCCL and brine (25 mL), dried over Na2SO4 and concentrated to dryness. The crude was purified by flash chromatography (Tol / EtOAc 90: 10 to 80:20) to give Acceptor BCD (286 mg, 72%) as a white foam. 'HNMR (400 MHz, CDC13) 8 7.80 - 7.70 (m, 3H), 7.62 (d, J= 1.6 Hz, 1H), 7.40 (dtd, J= 10.2, 4.5, 2.9 Hz, 3H), 7.33 - 7.07 (m, 15H), 6.91 (d, J= 7.4 Hz, 1H), 5.84 - 5.72 (m, 1H), 5.46 (s, 1H), 5.25 - 5.17 (m, 1H), 5.15 - 5.10 (m, 2H), 5.04 - 4.94 (m, 2H), 4.80 - 4.71 (m, 2H), 4.66 (d, J= 11.3 Hz, 1H), 4.58 - 4.51 (m, 2H), 4.50 - 4.42 (m, 2H), 4.38 (d, J= 11.6 Hz, 1H), 4.34 - 4.22 (m, 3H), 4.09 - 3.98 (m, 2H), 3.95 - 3.88 (m, 3H), 3.81 - 3.59 (m, 3H), 3.57 - 3.44 (m, 3H), 3.43 - 3.19 (m, 3H), 2.82 (d, J= 3.4 Hz, OH), 1.18 (d, J= 6.3 Hz, 3H), 0.69 (d, J = 6.3 Hz, 3H).

[0446] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-O-levulinoyl-a-L-rhamnopyranosyl- ( 1 — >2)-3,4-di-O-benzyl-a-L-rhamnopyranosyl-( 1 — >3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-a-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido-P-D-glucopyranoside (ABCD). To a solution of Acceptor BCD (286 mg, 250 pmol, 1.0 equiv.) and Donor A (200 mg, 326 pmol, 1.3 equiv.) in anhydrous Tol (7.5 mL), was added 4A MS (500 mg). The suspension was stirred at rt for 30 min under Ar and cooled to 0 °C. After 5 min, TMSOTf (4.5 pL, 25 pmol, 0.1 equiv.) was added. After 30 min, EtsN was added. The suspension was filtered on a fritted funnel, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (Tol / EtOAc 90:0 to 80:20) to give compound ABCD (293 mg, 74%), as a white foam.

[0447] Example 5: Synthesis of acceptor ABCD from ABCD

[0448]

[0449] Allyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-( 1— >2)-3,4-di-O- benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl)-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (Acceptor ABCD). To a solution of tetrasaccharide ABCD (0.4 g, 0.25 mmol, 1.0 equiv.) in a mixture of anhydrous pyridine (3 mL) and AcOH (3 mL) stirred at rt under Ar, was added hydrazine monohydrate (50-60%, 27 pL, 0.30 mmol, 1.2 equiv.). The suspension was stirred for 15 min at 0 °C then for 1 h at rt under Ar. Following addition of water (15 mL) and DCM (20 mL), the two layers were separated and the aq. one was extracted twice with DCM (8 mL). The combined organic phases were washed with 5% aq. citric acid (100 mL) and brine (100 mL), dried over Na2SO4 and concentrated to dryness. The crude was directly purified by flash chromatography (Tol / EtOAc 95:5 to 85: 15) to give the desired acceptor ABCD (329 mg, 88%) as a whitish crystalline solid.JH NMR (400 MHz, CDCh) 5 (ppm): 7.85-7.82 (m, 3H, Ctf-Ar), 7.68 (s, 1H, Ctf-Ar), 7.52-7.45 (m, 5H, Ctf-Ar), 7.38—7. 16 (m, 19H, Ctf-Ar), 7.02 (d, J= 7.4 Hz, 1H, WTCA), 5.93-5.83 (m, 1H, H-2AII), 5.56 (s, 1H, H-7D), 5.30 (ddd, J = 17.2, 3.5, 1.3 Hz, 1H, H-3aAn), 5.24-5.22 (m, 2H, H-2A, H-3bAii), 5.09-5.07 (m, 2H, H-1D, H-1B), 5.04 (d, Ju= 1.6 Hz, 1H, H-1A), 4.87 (br s, 1H, H-1C), 4.86-4.80 (m, 3H, C / ZHPh), 4.60-4.45 (m, 6H, H-3D, C / ZHPh), 4.41 —4.33 (m, 2H, H-6aD, H-laAii), 4. 13—4.08 (m, 2H, H-3C, H-lbAn), 4.06-3.95 (m, 5H, H-3B, C#2CA, H-2A, H-5C) 3.93 (dd, J= 3.4, 1.8 Hz, 1H, H-2B), 3.87-3.73 (m, 3H, H-6bD, H-3A, H-5B), 3.69-3.55 (m, 3H, H-5A, H-4D, H-5D), 3.51 —3.33 (m, 4H, H-2D, H-4A, H-4B, H-4C), 1.23 (d, J= 6.2 Hz, 3H, H-6A), 1.10 (d, J= 6.2 Hz, 3H, H-6B), 0.98 (s, 9H, C(CH3)3), 0.71 (d, J= 6.2 Hz, 3H, H- 6C), 0.15 (s, 6H, C / CSi). HRMS (ESI-TOF): m / z [M+NH4]+calcd for C76H95C14N2Oi9Si 1507.5047; found 1507.5022.

[0450] Example 6: Synthesis of donor ABCD

[0451]

[0452] 4-O-Benzyl-3-O-ter?-butyldimethylsilyl-2-O-levulinoyl-«-L-rhamnopyranosyl-( 1— >2)-3,4- di-f?-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido-a7?-D- glucopyranose (14). To a solution of tetrasaccharide ABCD (0.5 g, 0.31 mmol, 1.0 equiv.) in DCM / H2O (3: 1, 3 mL) stirred at rt, was added PdCh (60%, 6.5 mg, 0.022 mmol, 0.07 equiv.). The mixture was stirred for 3 h at 50 °C. A solution of NIS (85 mg, 0.38 mmol, 1.2 equiv.) in THF / H2O (4: 1, 3 mL) was poured at 0 °C and the mixture was stirred for 2 h from 0 °C to rt. 10% aq. Na2S2C>3 (8 mL) was added and the suspension was filtered over a pad of Celite and cotton. THF and DCM were removed under reduced pressure and EtOAc (50 mL) was added. The aqueous layer was extracted with EtOAc (2 x 100 mL) and the combined organic phases were washed with satd aq. NaHCOs (50 mL) and brine (50 mL), dried over anhydrous Na2SO4 and concentrated to dryness under vacuo. The residue was purified by flash chromatography (Tol / EtOAc 95:5 to 8:2) to give 14 (401 mg, 82%, a / p 10: 1.7) as a whitish crystalline solid.JH NMR (400 MHz, CDCI3) 5 (ppm): 7.85-7.80 (m, 3H, Ctf-Ar), 7.68 (s, 1H, Ctf-Ar), 7.51 —7.45 (m, 4H, Ctf-Ar), 7.37—7.16 (m, 19H, Ctf-Ar), 6.90 (d, J= 9.5 Hz, 1H, WTCA), 5.56 (s, 1H, H- 7D), 5.27 (t, J= 4.2 Hz, 1H, H-1D), 5.23 (dd, J= 3.3, 1.9 Hz, 1H, H-2A), 5.17 (dd, J= 3.3, 2.2 Hz, 1H, H-2C), 5.06 (d, Ji,2= 1.5 Hz, 1H, H-1B), 4.93 (d, Ji,2= 1.9 Hz, 1H, H-1C), 4.9O (d, Ji,2= 1.8 Hz, 1H, H-1A), 4.89-4.79 (m, 3H, C / ZHPh), 4.64-4.51 (m, 3H, CHflPh), 4.32-4.26 (m, 2H, H-6aD, H-2D), 4.18-4.08 (m, 4H, H-3C, H-5D, H-3A, H-3D), 4.02 (s, 2H, CH2CA), 3.99-3.93 (m, 2H, H-5C, H-2B), 3.83-3.65 (m, 5H, H-6bD, H-5A, H-3B, H-5B, H-4D), 3.44 (t, J= 9.5 Hz, 1H, H-4B), 3.36 (t, J= 9.4 Hz, 1H, H-4C), 3.28 (t, J= 9.2 Hz, 1H, H-4A), 3.18 (dd, J= 3.8, 1.5 Hz, 1H, OH), 2.76-2.65 (m, 4H, 2 x CH2Lev), 2.20 (s, 3H, CTLi.ev), 1.26 (d, J = 6.2 Hz, 3H, H-6B), 1.08 (d, J= 6.3 Hz, 3H, H-6A), 0.92 (s, 9H, C(C / f3)3), 0.70 (d, J= 6.2 Hz, 3H, H-6C), 0.13 (s, 3H, CT / iSi), 0.10 (s, 3H, CT / iSi). HRMS (ESI-TOF): m / z [M+NH4]+calcd for C78H97C14N2O2iSi 1565.5102; found 1565.5068. 4-O-Benzyl-3-O-tert-butyldimethylsilyl-2-O-levulinoyl-«-L-rhamnopyranosyl-( 1— >2)-3,4- di-t?-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido-a7?-D- glucopyranosyl (7V-phenyl)trifluoroacetimidate (Donor ABCD). To a solution of hemiacetal 14 (389 mg, 0.25 mmol, 1.0 equiv.) in anhydrous acetone (5 mL) stirred at rt under Ar, were successively added PTFAC1 (0.06 mL, 0.38 mmol, 1.5 equiv.) and K2CO3 (69 mg, 0.50 mmol, 2.0 equiv.). The mixture was stirred for 1 h at rt. After that time, the reaction mixture was filtered over a pad of Celite and the filtrate was concentrated to dryness under vacuo. The residue was purified (cHex / EtOAc 9: 1 to 7:3 + 1% TEA) to give donor ABCD (424 mg, 98%, a / p 10:0.6) as a crystalline solid. *HNMR (400 MHz, CDCI3) 5 (ppm): 7.85-7.82 (m, 3H, CH- Ar), 7.69 (s, 1H, Ctf-Ar), 7.52-7.44 (m, 5H, Ctf-Ar), 7.38-7.13 (m, 20H, Ctf-Ar), 6.80 -6.75 (m, 3H, Ctf-Ar), 6.89-6.84 (m, 3H, Ctf-Ar), 6.39 (br s, 1H, H-1D), 5.60 (s, 1H, H-7D), 5.23 (dd, J= 3.5, 2.0 Hz, 1H, H-2A), 5.17 (dd, J= 3.2, 2.1 Hz, 1H, H-2C), 5.04 (d, Ji,2= 1.6 Hz, 1H, H-1B), 5.00 (d, 71,2 = 1.7 Hz, 1H, H-1C), 4.91 (d, Ji,2= 1.8 Hz, 1H, H-1A), 4.89-4.82 (m, 3H, CZ / HPh), 4.64-4.47 (m, 6H, H-2D, CHflPh), 4.37 (dd, J = 10.4, 4.8 Hz, 1H, H-6aD), 4.18^4.12 (m, 3H, H-3A, H-3D, H-3C), 4.04 (s, 2H, C#2CA), 4.03-3.94 (m, 3H, H-5D, H-5C, H-2B), 3.84-3.75 (m, 4H, H-4D, H-6bD, H-5A, H-3B), 3.71 -3.64 (m, 1H, H-5B), 3.45 (t, J= 9.3 Hz, 1H, H-4B), 3.36 (t, J= 9.3 Hz, 1H, H-4C), 3.32 (t, J= 9.3 Hz, 1H, H-4A), 2.77-2.66 (m, 4H, 2 x CZ72Lev), 2.20 (s, 3H, C / f3Lev), 1.24 (d, J= 6.1 Hz, 3H, H-6B), 1.09 (d, J= 6.2 Hz, 3H, H-6A), 0.92 ( 0.74 (d, J= 6.1 Hz, 3H, H-6C), 0.14 (s, 3H, C#3Si), 0.11 (s,

[0453] 3H, CTLSi). HRMS (ESI-TOF): m / z [M+NH4]+calcd for CseHioiCUFsNsChiSi 1736.5398; found 1736.5381.

[0454] Example 7: Synthesis of octasaccharide [ABCDJi Allyl 4-O-benzyl-3-O-terCbutyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl- ( 1 — >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1 — >3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 — >2)-4-O-benzyl-3-O-tert-butyldimethylsilyl-«- L-rhamnopyranosyl-( 1— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (ABCD)i. To a solution of acceptor ABCD (329 mg, 0.22 mmol, 1.0 equiv.) in anhydrous toluene (6 mL) stirred at rt under Ar, were successively added donor ABCD (417 mg, 0.24 mmol, 1.1 equiv.) and activated 4A MS (0.21 g). The suspension was stirred for 15 min at rt under Ar atm, then cooled to — 35 °C and stirred for another 10 min. TBSOTf (7 qL, 0.03 mmol, 0.13 equiv.) was slowly added at this temperature. The mixture was then stirred for 30 min from — 35 °C to — 30 °C under Ar. EtsN (4 qL, 0.031 mmol, 0.14 equiv.) was added. The suspension was stirred for 10 min at — 30 °C, and filtered over a pad of Celite. The filtrate was concentrated under reduced pressure and purified by flash chromatography (cHex / EtOAc 95:5 to 8:2) to give the desired octasaccharide (ABCD)i (0.43 g, 65%) as a whitish crystalline solid. The target compound had Ry 0.7 (Tol / EtOAc 8:2); HRMS (ESI-TOF): m / z [M+NH4]+calcd for Ci54Hi9oCi8N4039Si2 1527.5021; found 1527.5020.

[0455] Example 8: Bzl group removal from tetrasaccharide ABCD

[0456] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl- ( 1 — >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1 — >3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-«-L-rhamnopyranosyl-( 1— >3)-2-deoxy-2-trichloroacet amido- / ?-D- glucopyranoside (17). To a solution of tetrasaccharide ABCD (4.0 g, 2.515 mmol, 1.0 equiv.) in anhydrous DCM (50 mL) stirred at rt under Ar, were successively added CSA (584 mg, 2.515 mmol, 1.0 equiv.) and 1,2-dithioethane (422 qL, 5.03 mmol, 2.0 equiv.). The suspension was stirred overnight at rt under Ar. Following addition of DCM (200 mL), the solution was poured into a separatory funnel, washed with saturated NaHCCL (2 x 70 mL), with water (70 mL) and brine (70 mL), dried over Na2SO4 and concentrated to dryness. The crude was directly purified by flash chromatography (Tol / EtOAc 95:5 to 8:2) to give compound 17 (3.21 g, 85%), as a crystalline solid. 'HNMR (400 MHz, CDCI3) 5 (ppm): 7.87-7.82 (m, 3H, Ctf-Ar), 7.73 (s, 1H, Ctf-Ar), 7.52-7.47 (m, 2H, Ctf-Ar), 7.42-7. 14 (m, 19H, Ctf-Ar), 6.93 (d, J = 7.6 Hz, 1H, WTCA), 5.93-5.83 (m, 1H, H-2AII), 5.30 (ddd, J= 17.3, 3.6, 1.5 Hz, 1H, H-3aAn), 5.25 (dd, J = 3.4, 2.3 Hz, 1H, H-2C), 5.23-5.20 (m, 2H, H-2A, H-3bAn), 5.01 (d, Ji,2= 1.7 Hz, 1H, H-1B), 4.92 (d, Ji,2 = 8.2 Hz, 1H, H-1D), 4.90-4.86 (m, 6H, H-1A, H-1C, C / ZHPh), 4.64-4.57 (m, 4H, C / ZHPh), 4.52 (d, J= 11.9 Hz, 1H, C / ZHPh), 4.35 (ddd, J= 13.0, 5.3, 1.5 Hz, 1H, H-laAii), 4.16-4.06 (m, 6H, H-3A, H-3C, H-lbAn, C#2CA, H-3D), 4.01 -3.93 (m, 3H, H-5C, H-6aD, H- 2B), 3.85-3.76 (m, 3H, H-6bD, H-5A, H-3B), 3.64-3.57 (m, 1H, H-5B), 3.54-3.39 (m, 5H, H-2D, H-4D, H-4C, H-4B, H-5D), 3.35 (t, J= 9.3 Hz, 1H, H-4A), 2.77^2.67 (m, 4H, 2 x CZ72Lev), 2.21 (s, 3H, C#3Lev), 1.26 (d, J= 6.2 Hz, 3H, H-6C), 1.20 (d, J= 6.3 Hz, 3H, H-6A), 1.18 (d, J= 6.1 Hz, 3H, H-6B), 0.94 (s, 9H, C(CH3)3), 0.15 (s, 3H, C#3Si), 0.12 (s, 3H, C#3Si). HRMS (ESI-TOF): m / z [M+NH4]+calcd for C74H97Cl4N2O2iSi 1517.5102; found 1517.5078.

[0457] Example 9: Nap group removal from tetrasaccharide ABCD

[0458] ABCD 20

[0459] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl- ( 1 — >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1 — >3)-2-O-chloroacetyl-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (20). To a solution of tetrasaccharide ABCD (2.0 g, 1.257 mmol, 1.0 equiv.) in DCM / H2O (20: 1, 52.5 mL) stirred at rt under Ar, were successively added portionwise DDQ (856 mg, 3.772 mmol, 3.0 equiv.) and P-pinene (1.8 mL, 12.57 mmol, 10 equiv.). The suspension was stirred overnight at rt under Ar. After that time, solid NaHCCL was added and the reaction mixture was stirred for another 15 min. Following addition of DCM (200 mL), the solution was poured into a separatory funnel, washed with saturated NaHCCL (3 x 50 mL), with water (50 mL) and brine (50 mL), dried over Na2SO4and concentrated to dryness. The crude was directly purified by flash chromatography (Tol / EtOAc 95:5 to 8:2) to give compound 20 (1.42 g, 78%), as a crystalline yellow solid. 'H NMR (400 MHz, CDCh) 5 (ppm): 7.51 —7.48 (m, 2H, Ctf-Ar), 7.38-7.28 (m, 20H, Ctf-Ar), 7.04 (d, J= 7.8 Hz, 1H, WTCA), 5.92-5.82 (m, 1H, H-2AII), 5.55 (s, 1H, H-7D), 5.29 (ddd, J = 17.1, 4.5, 1.6 Hz, 1H, H-3aAn), 5.24— 5. 18 (m, 3H, H-2C, H-2A, H-3bAn), 5.08 (d, Ji,2= 8.1 Hz, 1H, H-1D), 5.03 (d, Ji,2= 3.4 Hz, 1H, H-1B),

[0460] 4.91 (d, J= 11.0 Hz, 1H, C / ZHPh), 4.88 (d, JI,2= 2.1 Hz, 1H, H-1A), 4.83 (d, Ji,2= 1.2 Hz, 1H, H-1C), 4.71 (d, J = 11.4 Hz, 1H, C / ZHPh), 4.65 (s, 2H, C / ZHPh), 4.59 (d, J = 11.9 Hz, 1H, C / ZHPh), 4.57-4.49 (m, 2H, H-3D, C / ZHPh), 4.41 —4.33 (m, 2H, H-6aD, H-laAn), 4.18 (dd, J = 9.1, 3.4 Hz, 1H, H-3A), 4.10 (ddd, J = 12.8, 6.3, 1.3 Hz, 1H, H-lbAn), 3.98 (s, 2H, C#2CA),

[0461] 3.91 -3.78 (m, 5H, H-5A, H-3C, H-2B, H-5C, H-6bD), 3.72 (dd, J = 7.0, 2.8 Hz, 1H, H-3B), 3.65-3.55 (m, 3H, H-5B, H-4D, H-5D), 3.49-3.34 (m, 4H, H-2D, H-4C, H-4B H-4A), 2.80-2.66 (m, 4H, 2 x C#2Lev), 2.23 (s, 3H, CWev), 1.24 (d, J= 6.2 Hz, 3H, H-6A), 1.22 (d, J = 6.2 Hz, 3H, H-6B), 0.93 (s, 9H, C(C#3)3), 0.68 (d, J= 6.1 Hz, 3H, H-6C), 0.15 (s, 3H, C#3Si), 0.13 (s, 3H, C#3Si). HRMS (ESI-TOF): m / z [M+NH4]+calcd for C7oH93Cl4N202iSi 1465.4789; found 1465.4772.

[0462] Example 10: TBS group removal from tetrasaccharide ABCD

[0463] Allyl 4-O-benzyl-2-CMevulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (21). To a solution of tetrasaccharide ABCD (2.0 g, 1.257 mmol, 1.0 equiv.) in anhydrous THF (82 mL) stirred at rt under Ar, was added EtsN 3HF (12.3 mL, 75.446 mmol, 60.0 equiv.). The suspension was stirred for 2 days at 30 °C under Ar, then cooled to rt. Following addition of EtOAc (200 mL), the solution was washed with a cooled saturated NaHCCE (3 x 70 mL), water (70 mL) and brine (70 mL), dried over Na2SO4and concentrated to dryness. The crude was directly purified by flash chromatography (Tol / EtOAc 95:5 to 8:2) to give compound 21 (1.55 g, 84%), as a crystalline solid.XH NMR (400 MHz, CDCI3) 5 (ppm): 7.87-7.83 (m, 3H, Ctf-Ar), 7.70 (s, 1H, Ctf-Ar), 7.52-7.47 (m, 4H, Ctf-Ar), 7.39—7. 18 (m, 23H, Ctf-Ar), 7.10 (d, J= 7.0 Hz, 1H, WTCA), 5.94-5.84 (m, 1H, H-2An), 5.58 (s, 1H, H-7D), 5.34-5.28 (m, 2H, H-2A, H-3aAn), 5.25-5.22 (m, 2H, H-3bAn, H-2C), 5.08 (d, Ji,2= 8.0 Hz, 1H, H-1D), 5.06 (d, Ji,2= 1.1 Hz, 1H, H-1B), 4.95 (d, Ji,2= 1.4 Hz, 1H, H-l A), 4.91 -4.87 (m, 3H, CWHPh, H-1C), 4.83 (d, J= 11.5 Hz, 1H, CZ / HPh), 4.69-4.51 (m, 6H, H-3D, CWHPh), 4.42-4.34 (m, 2H, H-6aD, H-laAn), 4.18-4.09 (m, 3H, H-3A, H-lbAn, H-3C), 4.04 (s, 2H, C / / 2c \), 4.02-3.98 (m, 1H, H-5C), 3.96 (t, J = 2.4 Hz, H-2B), 3.83-3.77 (m, 3H, H-5A, H- 3B, H-6bD), 3.72-3.56 (m, 3H, H-5B, H-4D, H-5D), 3.54-3.45 (m, 2H, H-2D, H-4B), 3.33 (td, J= 15.3, 9.6 Hz, 2H, H-4C, H-4A), 2.87-2.57 (m, 4H, 2 x C#2Lev), 2.21 (s, 3H, CH^\ 1.27 (d, J= 6.2 Hz, 3H, H-6B), 1.17 (d, J= 6.3 Hz, 3H, H-6A), 0.71 (d, J= 6.1 Hz, 3H, H-6C). HRMS (ESI-TOF): m / z [M+NH4]+calcd for C75H87C14N2O2I 1491.4550; found 1491.4555.

[0464] Example 11: Selective benzylation at position 6D

[0465] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-CMevulinoyl-«-L-rhaninopyranosyl- ( 1 — >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1 — >3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-«-L-rhamnopyranosyl-( 1— >3)-2-deoxy-2-trichloroacet amido- / ?-D- glucopyranoside (22). To a solution of diol 17 (3.2 g, 2.14 mmol, 1.0 equiv.) in anhydrous ACN (214 mL) stirred at rt under Ar, were successively added Taylor’s reagent (223 mg, 0.428 mmol, 0.2 equiv.), Ag2O (992 mg, 4.28 mmol, 2.0 equiv.) and BnBr (1018 qL, 8.56 mmol, 4.0 equiv.). The suspension was stirred overnight at 60 °C under Ar. After that time, the reaction mixture was cooled to rt, and the suspension was filtered over Celite, rinsed with DCM (200 mL) and solvents were evaporated under reduced pressure. The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 75:25) to give compound 22 (2.41 g, 71%), as a crystalline yellow solid. 'H NMR (400 MHz, CDC13) 5 (ppm): 7.88-7.84 (m, 3H, Ctf-Ar), 7.76 (s, 1H, Ctf-Ar), 7.53-7.48 (m, 2H, Ctf-Ar), 7.45-7. 15 (m, 19H, Ctf-Ar), 6.94 (d, J = 7.7 Hz, 1H, NTTTCA), 5.94-5.84 (m, 1H, H-2AII), 5.33-5.26 (m, 2H, H-3aAn, H-2C), 5.25 (dd, J = 3.3, 2.0 Hz, 1H, H-2A), 5.21 (ddd, J= 10.5, 1.6, 1.2 Hz, 1H, H-3bAn), 5.04 (d, Ji,2= 1.4 Hz, 1H, H-1B), 4.91 —4.87 (m, 6H, H-1C, H-1A, H-1D, C / ZHPh), 4.68-4.58 (m, 6H, C / ZHPh), 4.53 (d, J = 12.0 Hz, 1H, C / ZHPh), 4.38 (ddd, J= 12.9, 5.3, 1.5 Hz, 1H, H-laAn), 4.17 (dd, J= 8.9, 3.3 Hz, 1H, H-3A), 4.14— 4.07 (m, 5H, H-3C, H-lbAn, CH2CK, H-3D), 4.04-3.98 (m, 1H, H-5C), 3.96 (dd, J= 3.1, 2.0 Hz, 1H, H-2B), 3.88-3.73 (m, 4H, H-6aD, H-5A, H-3B, H-6bD), 3.67-3.59 (m, 1H, H-5B), 3.58-3.48 (m, 4H, H-2D, H-4D, H-5D, H-4C), 3.45 (t, J= 9.4 Hz, 1H, H-4B), 3.36 (t, J= 9.5 Hz, 1H, H-4A), 2.78-2.67 (m, 4H, 2 x CH2Lev), 2.21 (s, 3H, Cftkv), 1.27 (d, J = 6.2 Hz, 3H, H-6C), 1.21 (d, J= 6.3 Hz, 3H, H-6A, H-B), 0.95 0.16 (s, 3H,

[0466] C#3Si), 0.14 (s, 3H, CftSi). HRMS (ESI-TOF): m / z [M+NH4]+calcd for CsiHiosCU^ChiSi 1607.5571; found 1607.5578.

[0467] Example 12: Synthesis of pentasaccharide ABC(E4)D 28 (la / lb)

[0468] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-O-levulinoyl-«-L-rhamnopyranosyl- ( 1 — >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1 —>3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside

[0469] (28). To a solution of acceptor 22 (2.4 g, 1.51 mmol, 1.0 equiv.) in anhydrous DCM / Et2O (1 :5, 35 mL), were added DMF (704 pL, 9.09 mmol, 6.0 equiv.) and activated ground molecular sieves (4A, 5 g). The mixture was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -60 °C. After 5 min, TfOH (335 pL, 3.79 mmol, 2.5 equiv.) was added. Then a solution of PTFA donor Ea / b (1.8 g, 2.57 mmol, 1.7 equiv.) in anhydrous DCM / Et2O (1.5:4, 13 mL) was slowly added over 1 h from -60 to -50 °C. After that time, the reaction mixture was allowed to stir under Ar overnight while being gradually warmed to rt. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (50 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 28 (2.48 g, 77%), as a crystalline solid.JH NMR (400 MHz, CDCh) 5 (ppm): 7.85—7.81 (m, 3H, Ctf-Ar), 7.74 (s, 1H, Ctf-Ar), 7.52-7.48 (m, 2H, Ctf-Ar), 7.42^7.11 (m, 47H, Ctf-Ar), 5.98-5.88 (m, 1H, H-2AII), 5.32 (ddd, J = 17.3, 3.6, 1.5 Hz, 1H, H-3aAii), 5.29-5.26 (m, 2H, H-2C, H-2A), 5.22 (ddd, J= 10.5, 3.5, 1.5 Hz, 1H, H-3bAn), 5.11 (d, Ji,2= 1.2 Hz, 1H, H-1B), 5.07 (d, Ji,2= 1.4 Hz, 1H, H-1C), 4.93-4.78 (m, 10H, H-1A, H-1E, H-1D, C / ZHPh), 4.68-4.44 (m, 11H, C / ZHPh), 4.32-4.23 (m, 3H, H-laAn, C / ZHPh, H-2D), 4.17—4.05 (m, 6H, H-3A, C#2CA, H-3D, H-3C, H-lbAn), 4.03-3.98 (m, 3H, H-6aD, H-6bD, H-4D), 3.96-3.90 (m, 2H, H-2B, H-3E), 3.83 (dd, J= 9.4, 2.7 Hz, 1H, H-3B), 3.81 -3.63 (m, 7H, H-5A, H-5E, H-5B, H-5D, H-5C, H-4E, H-6aE), 3.57-3.50 (m, 2H, H-2E, H-4C), 3.48 (t, J= 9.5 Hz, 1H, H-4B), 3.39 (dd, J= 10.9, 1.4 Hz, 1H, H-6bE), 3.31 (t, J= 9.3 Hz, 1H, H-4A), 2.76-2.66 (m, 4H, 2 x C#2Lev), 2.20 (s, 3H, CWev), 1.28 (d, J= 6.1 Hz, 3H, H-6B), 1.17 (d, J = 6.1 Hz, 3H, H-6C), 1.02 (d, J= 6.2 Hz, 3H, H-6A), 0.93 (s, 9H, C(CH3)3), 0.14 (s, 3H, C#3Si), 0.10 (s, 3H, C#3Si). HRMS (ESI-TOF): m / z [M+NH4]+calcd for Cii5Hi37C14N2O26Si 2129.7977; found 2129.7980.

[0470] Example 13: Synthesis of pentasaccharide AB(E)CD 31 (2a)

[0471] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-CMevulinoyl-«-L-rhaninopyranosyl- (1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O- benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (31). To a solution of acceptor 20 (3.6 g, 2.459 mmol, 1.0 equiv.) in anhydrous Toluene (74 mL), were added DMF (1.33 mL, 17.2 mmol, 7.0 equiv.) and activated ground molecular sieves (4A, 3.5 g). The mixture was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -35 °C. After 5 min, TfOH (544 pL, 6.15 mmol, 2.5 equiv.) was added. Then a solution of PTFA donor Ea (3.5 g, 4.92 mmol, 2.0 equiv.) in anhydrous Toluene (49 mL) was slowly added over 1 h from -35 to -30 °C. After that time, the reaction mixture was allowed to stir under Ar overnight while being gradually warmed to rt. Et3N was added. The suspension was filtered over Celite, rinsed with DCM (50 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 31 (4.28 g, 88%), as a crystalline yellow solid. 'H NMR (400 MHz, CDCh) 5 (ppm): 7.48— 7.18 (m, 41H, C / f-Ar), 7.04 (d, J = 5.8 Hz, 1H, WTCA), 5.94-5.84 (m, 1H, H-2AII), 5.56 (s, 1H, H-7D), 5.34-5.30 (m, 2H, H-3aAn, H-2A), 5.25-5.22 (m, 2H, H-3bAn, H-2C), 5.08 (d, JID,2D = 7.5 Hz, 1H, H-1D), 5.05 (s, 1H, H-1A), 4.96-4.81 (m, 9H, H-1B, H-1E, H-1C, CWHPh), 4.66-4.49 (m, 10H, C / THPh, H-3D), 4.41 -4.35 (m, 4H, H-6aD, C / ZHPh, H-3C, H-laAn), 4.22 (dd, J = 9.2, 3.1 Hz, 1H, H-3A), 4.12 (ddd, J = 12.7, 1.8, 1.0 Hz, 1H, H-lbAn), 4.01 (s, 2H, CH2CA), 3.97-3.87 (m, 4H, H-5A, H-5C*, H-5E*, H-2B), 3.84-3.65 (m, 5H, H-3E, H-6bD, H-6aE, H- 4E, H-3B), 3.63^3.51 (m, 3H, H-4D, H-5D, H-5B), 3.48-3.38 (m, 5H, H-2D, H-4C, H-4B, H-4A, H-2E), 2.73-2.52 (m, 4H, 2 x CH2Lev), 2.12 (s, 3H, C#3Lev), 1.33 (d, J= 6.2 Hz, 3H, H- 6 A), 1.17 (d, J= 6.2 Hz, 3H, H-6B), 0.93 (s, 9H, C(CH2)2), 0.82 (d, J= 6.1 Hz, 3H, H-6C), 0.16 (s, 3H, C#3Si), 0.13 (s, 3H, C#3Si). HRMS (ESI-TOF): m / z [M+NH4]+calcd for Cio4Hi27C14N2026Si 1987.7195; found 1987.7195.

[0472] Example 14: Synthesis of pentasaccharide (E)ABCD 32 (3a)

[0473] Allyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1 — >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (32).

[0474] To a solution of acceptor 21 (4.7 g, 3.24 mmol, 1.0 equiv.) in anhydrous DCMZEt2O (1 :5, 68 mL), were added DMF (1.76 mL, 22.71 mmol, 7.0 equiv.) and activated ground molecular sieves (4A, 9.5 g). The mixture was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -50 °C. After 5 min, TfOH (718 pL, 8.1 mmol, 2.5 equiv.) was added. Then a solution of PTFA donor Ea (3.3 g, 4.8 mmol, 1.5 equiv.) in anhydrous DCMZEt2O (1 :3, 19 mL) was slowly added over 1 h from -50 to -40 °C. After that time, the reaction mixture was allowed to stir under Ar overnight while being gradually warmed to rt. Et3N was added. The suspension was filtered over Celite, rinsed with DCM (100 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (TolZEtOAc 95:5 to 8:2) to give compound 32 (6.39 g, 98%), as a crystalline solid.JH NMR (400 MHz, CDCI3) 5 (ppm): 7.87-7.83 (m, 3H, Ctf-Ar), 7.69 (s, 1H, Ctf-Ar), 7.53-7.47 (m, 4H, Ctf-Ar), 7.41 —7.08 (m, 37H, Ctf-Ar), 7.05 (d, J= 7.2 Hz, 1H, WTCA), 5.94-5.84 (m, 1H, H-2AII), 5.57 (s, 1H, H-7D), 5.54 (t, J= 2.3 Hz, H-2A), 5.31 (ddd, J= 17.3, 3.6, 1.4 Hz, 1H, H-3aAn), 5.26-5.23 (m, 3H, H- 1E, H-2C, H-3bAn), 5.11 (d, J = 8.2 Hz, 1H, H-1D), 5.04-5.01 (m, 2H, H-1B, C / ZHPh), 4.98 (br s, 1H, H-1A), 4.95-4.77 (m, 7H, H-1C, C / THPh), 4.69-4.49 (m, 10H, H-3D, C / ZHPh), 4.43-4.33 (m, 3H, H-6aD, C / ZHPh, H-laAn), 4.24 (dd, J= 9.5, 3.0 Hz, 1H, H-3A), 4.17-3.99 (m, 7H, H-lbAii, H-3E, H-3C, CHZCK, H-5E, H-5C), 3.97 (t, J= 2.4 Hz, H-2B), 3.87-3.79 (m, 4H, H-5A, H-6bD, H-4E, H-3B), 3.70-3.44 (m, 9H, H-5B, H-6aE, H-4D, H-2E, H-5D, H-6bD, H-4A, H-4B, H-2D), 3.34 (t, J= 9.5 Hz, 1H, H-4A), 2.58-2.36 (m, 4H, 2 x CH2Lev), 2.07 (s, 3H, OTLev), 1.27 (d, J= 6.2 Hz, 3H, H-6B), 1.21 (d, J= 6.2 Hz, 3H, H-6A), 0.71 (d, J= 6.2 Hz, 3H, H-6C). HRMS (ESI-TOF): m / z [M+NH4]+calcd for C109H121CI4N2O26 2013.6956; found 2013.6970.

[0475] Example 15: Synthesis of homo-oligosaccharides

[0476] Synthesis of pentasaccharide donors (lb, 2a and 3a)

[0477] General procedure for PTFA activation.

[0478] To a solution of oligosaccharide (1.0 equiv.) in DCM / H2O (3: 1, 10 mL.mmol) stirred at rt, was added PdCL (0.07 equiv.). The mixture was stirred for 3 h at 50 °C. Then, a solution of NIS (1.2 equiv.) in THF / H2O (4: 1, 7 mL.mmol) was poured into the previous solution at 0 °C and the obtained suspension was stirred for 3 h at rt. The reaction mixture was filtered over a pad of Celite and cotton and rinsed with DCM. 10% Aq. Na2S20s was added and the organic phase was washed with a saturated aq. NaHCCL and brine, dried over Na2SO4 and concentrated to dryness. To a solution of the obtained crude hemiacetal (1.0 equiv.) in anhydrous acetone (20 mL.mmol) stirred at rt under Ar, were successively added PTFAC1 (1.5 equiv.) and K2CO3 (2.0 equiv.). The suspension was stirred for 1 h at rt, filtered over a pad of Celite and the filtrate was concentrated under reduced pressure and purified by flash chromatography.

[0479] 4-O-Benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl-( 1— >2)-3,4- di-f?-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido-a / p-D-glucopyranosyl (N- phenyl)trifluoroacetimidate (33). The title compound was synthesized from pentasaccharide 28 (250 mg, 0.118 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (cHex / EtOAc 95:5 to 7:3) gave compound 33 (200 mg, 93%, over 2 steps) as a crystalline solid along with traces of its corresponding oxazoline.JH NMR (400 MHz, CDC13) 5 (ppm): 7.84-7.79 (m, 4H, Ctf-Ar), 7.71 (s, 1H, Ctf-Ar), 7.63 (d, J = 8.7 Hz, 1H, NZ / TCA), 7.51 -7.47 (m, 2H, Ctf-Ar), 7.39-7.07 (m, 47H, Ctf-Ar), 6.84 (d, J = 7.6 Hz, 2H, Ctf-Ar), 6.40 (br s, 1H, H-1D), 5.25 (dd, J= 3.3, 2.0 Hz, 1H, H-2A), 5.20 (t, J = 3.4 Hz, 1H, H-2C), 5.09 (s, 1H, H-1B), 4.99 (s, 1H, H-1C), 4.94-4.78 (m, 11H, H-1A, H-1E, C / ZHPh), 4.65-4.45 (m, 14H, H-2D, C / ZHPh), 4.31 (d, J= 12.1 Hz, 1H, C / ZHPh), 4.21 -4.07 (m, 3H, H-5D, H-3A, H-3C), 4.05 (d, J= 1.5 Hz, 2H, CH2CA), 4.02 (dd, J= 5.1, 2.9 Hz, 1H, H- 3D), 3.94 (t, J= 3.3, 1H, H-2B), 3.89 (t, J= 9.2, 1H, H-3E), 3.81 —3.74 (m, 7H, H-5A, H-4D, H-3B, H-5C, H-6aD, H-6bD, H-5E), 3.73-3.54 (m, 4H, H-5B, H-4E, H-6aE, H-2E), 3.49-3.40 (m, 3H, H-4C, H-4B, H-6bE), 3.30 (t, J= 9.3 Hz, 1H, H-4A), 2.76-2.66 (m, 4H, 2 x CH2^, 2.20 (s, 3H, CZZsLev), 1.19 (d, J= 6.0 Hz, 3H, H-6B), 1.12 (d, J= 6.2 Hz, 3H, H-6C), 1.02 (d, J = 6.2 Hz, 3H, H-6A), 0.92 (s, 9H, C(CHX)2\ 0.13 (s, 3H, C#3Si), 0.08 (s, 3H, C#3Si). HRMS (ESI-TOF): m / z [M+NH4]+calcd for C^oH^C^NsCheSi 2260.7960; found 2260.8042.

[0480] 4-O-Benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4- di-O-benzyl-«-L-rhamnopyranosyl-(1^3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl- ( 1 — >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1 — >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido-a / p-D-glucopyranosyl (A-phenyl)trifluoroacetimidate (34). The title compound was synthesized from pentasaccharide 31 (250 mg, 0.127 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (cHex / EtOAc 95:5 to 7:3) gave compound 34 (195 mg, 93%, over 2 steps) as a crystalline solid. 'H NMR (400 MHz, CDCI3) 5 (ppm): 7.51 -7.49 (m, 2H, Ctf-Ar), 7.40-7. 14 (m, 47H, CH- Ar), 6.83 (d, J= 7.6 Hz, 1H, W’TCA), 6.81 (d, J= 7.1 Hz, 1H, WTCA), 6.42 (br s, 1H, H-1D), 5.61 (s, 1H, H-7D), 5.30 (br s, 1H, H-2A), 5.18 (t, J= 2.8 Hz, 1H, H-2C), 5.04-5.03 (m, 2H, H-1C, H-1A), 4.95-4.90 (m, 5H, H-1B, H-1E, C / ZHPh), 4.84 (d, J = 10.9 Hz, 1H, C / ZHPh), 4.83 (d, J= 10.9 Hz, 1H, C / ZHPh), 4.67-4.50 (m, 10H, H-2D, C / ZHPh), 4.41 -4.36 (m, 3H, H- 6aD, H-3C, C / ZHPh), 4.05 (dd, J = 9.3, 3.2 Hz, 1H, H-3A), 4.16^4.12 (m, 1H, H-3D), 4.03-3.73 (m, 10H, C / / 2CA, H-5D, H-5A, H-2B, H-5C, H-3E, H-5E, H-6bD, H-4D, H-6aE, H- 4E), 3.68 (dd, J= 9.3, 2.5 Hz, 1H, H-3B), 3.60-3.53 (m, 1H, H-5B), 3.48-3.37 (m, 4H, H-2E, H-4C, H-4B, H-4A), 2.70-2.53 (m, 4H, 2 x CH2L^ 2.13 (s, 3H, C#3Lev), 1.31 (d, J= 6.0 Hz, 3H, H-6A), 1.18 (d, J= 6.2 Hz, 3H, H-6B), 0.93 (s, 9H, C(C#3)3), 0.91 (d, J= 6.2 Hz, 3H, H- 6C), 0.17 (s, 3H, C#3Si), 0.13 (s, 3H, C#3Si). HRMS (ESI-TOF): m / z [M+NH4]+calcd for Cio9Hi27Cl4F3N3026Si 2118.7178; found 2118.7215.

[0481] [2,3,4,6-Tetra-O-benzyl-a-D-glucopyranosyl-( 1^3)]-4-O-benzyl-2-O-levulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl (A-phenyl)trifluoroacetimidate (35). The title compound was synthesized from pentasaccharide 32 (500 mg, 0.520 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (cHex / EtOAc 95:5 to 7:3) gave compound 35 (452 mg, 92%, over 2 steps) as a crystalline solid along with traces of its corresponding oxazoline. 'H NMR (400 MHz, CDC13) 5 (ppm): 7.88-7.84 (m, 3H, Ctf-Ar), 7.71 (s, 1H, Ctf-Ar), 7.54-7.48 (m, 4H, Ctf-Ar), 7.40-7.07 (m, 47H, Ctf-Ar), 6.82 (d, J = 7.9 Hz, 1H, N / TTCA), 6.78 (d, J= 9.0 Hz, 1H, NFTCA), 6.41 (br s, 1H, H-1D), 5.60 (s, 1H, H-7D), 5.54 (dd, J= 3.5, 2.1 Hz, 1H, H-2A), 5.23 (d, J= 3.4, 1H, H- 1E), 5.18 (t, J = 3.5 Hz, 1H, H-2C), 5.02 (br s, 2H, H-1B, H-1C), 4.99-4.82 (m, 7H, H-1A, C / THPh), 4.76 (d, J= 12.0 Hz, 1H, CWHPh), 4.69-4.47 (m, 10H, H-2D, CWHPh), 4.42-4.33 (m, 2H, H-6aD, C / ZHPh), 4.23 (dd, J = 9.8, 3.1 Hz, 1H, H-3A), 4.19-3.95 (m, 7H, H-3D, H- 3C, H-3E, C#2CA, H-5D, H-5C), 3.94 (t, J= 3.4 Hz, 1H, H-2B), 3.89-3.77 (m, 3H, H-5A, H- 6bD, H-3B), 3.71^3.61 (m, 3H, H-5B, H-6aE, H-2E), 3.57-3.48 (m, 3H, H-6bE, H-4A, H- 4B), 3.66 (t, J= 9.3 Hz, 1H, H-4C), 2.59-2.35 (m, 4H, 2 x C / f2Lev), 2.06 (s, 3H, C#3Lev), 1.28 (d, J= 6.0 Hz, 3H, H-6B), 1.22 (d, J= 6.2 Hz, 3H, H-6A), 0.76 (d, J= 6.2 Hz, 3H, H-6C). HRMS (ESI-TOF): m / z [M+NH4]+calcd for CII4H12IC14F3N3O262144.6939; found 2144.6983.

[0482] Synthesis of pentasaccharide acceptors (lb, 2a and 3a)

[0483] Allyl 3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1^2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (36a). To a solution of compound 28 (300 mg, 0.142 mmol, 1.0 equiv.) in a mixture of Py / AcOH (1 : 1, 4 mL) stirred at 0 °C under Ar, was added hydrazine monohydrate (50-60 %, 15 pL, 0.17 mmol, 1.2 equiv.). The mixture was stirred for 2 h while being gradually warmed to rt. Following addition of DCM (20 mL), the organic phase was washed several times with an aqueous solution of CuSCU Then, the combined organic phases were washed with water (10 mL), brine (10 mL) and dried over Na2SO4. The filtrate was concentrated under reduced pressure. The crude residue was dissolved in anhydrous THF (9 mL) and stirred at rt under Ar. TEA.3HF (1.4 mL, 8.5 mmol, 60 equiv.). was added and the reaction mixture was stirred at 30 °C overnight. The suspension was cooled to rt, diluted with EtOAc (20 mL), washed with saturated aqueous NaHCCh (10 mL), water (10 mL) and brine (10 mL), dried over Na2SO4 and concentrated to dryness. The crude was solubilized in anhydrous ACN (3.4 mL) and the mixture was stirred at rt under Ar. Iron-dibm complex (9.0 mg, 0.018 mmol, 0.2 equiv.), TBAB (5.6 mg, 0.018 mmol, 0.2 equiv.), Ag2O (15.0 mg, 0.86 mmol, 1.0 equiv.) and BnBr (31 pL, 0.256 mmol, 3.0 equiv.) were added to the suspension and the reaction was allowed to stirr at 40 °C for 45 min. The mixture was cooled down to rt and diluted with DCM, filtered through Celite and concentrated to dryness. The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 85: 15) to give compound 36a (163 mg, 82% over 3 steps), as a yellow oil.JH NMR (400 MHz, CDCh) 5 (ppm): 7.87—7.82 (m, 4H, Ctf-Ar), 7.77 (s, 1H, Ctf-Ar), 7.53-7.48 (m, 2H, Ctf-Ar), 7.43-7.24 (m, 41H, CH- Ar), 7.21 —7.09 (m, 5H, Ctf-Ar), 5.98-5.88 (m, 1H, H-2AII), 5.33 (ddd, J= 17.2, 3.9, 1.5 Hz, 1H, H-3aAn), 5.37 (dd, J = 3.4, 2.0 Hz, 1H, H-2C), 5.22 (ddd, J= 10.5, 3.3, 1.2 Hz, 1H, H- 3bAii), 5.11 (s, 1H, H-1B), 5.07 (d, Jic,2c = 1.4 Hz, 1H, H-1C), 5.06 (d, JIA,2A = 1.6 Hz, 1H, H- 1A), 4.96-4.78 (m, 9H, H-1D, H-1E, C / ZHPh), 4.68-4.43 (m, 11H, C / ZHPh), 4.30 (dd, J = 12.9, 5.0 Hz, 1H, H-laAn), 4.25—4.21 (m, 2H, C / ZHPh, H-2D), 4.15-3.99 (m, 10H, CHicx, H- 3C, H-5D, H-2A, H-lbAn, H-4D, H-6aD, H-2B, H-3D), 3.96-3.68 (m, 9H, H-3E, H-3B, H-3A, H-5A, H-5B, H-5E, H-5C, H-4E, H-6bD), 3.64 (dd, J= 10.8, 2.4 Hz, 1H, H-6aE), 3.59^3.51 (m, 2H, H-2E, H-4C), 3.44 (t, J= 9.4 Hz, 1H, H-4B) , 3.43 (t, J= 9.3 Hz, 1H, H-4A), 3.35 (d, J= 10.5 Hz, 1H, H-6bE), 2.43 (s, 1H, OH), 1.32 (d, J= 6.3 Hz, 3H, H-6B), 1.17 (d, J= 6.2 Hz, 3H, H-6C), 1.06 (d, J = 6.2 Hz, 3H, H-6A). HRMS (ESI-TOF): m / z [M+NH4]+calcd for C111H123CI4N2O242007.7214; found 2007.7240.

[0484] General procedure for the preparation of acceptors from the corresponding oligosaccharides (with pentasaccharide 36a as an exception).

[0485] To a solution of oligosaccharide (1.0 equiv.) in a mixture of Py / AcOH (1 : 1, 27 mL.mmol) stirred at 0 °C under Ar, was added hydrazine monohydrate (50-60%, 1.2 or 2.0 equiv.). The mixture was stirred for 1 h while being gradually warmed to rt. Following addition of DCM, the organic phase was washed several times with an aqueous solution of CuSCU Then, the combined organic phases were washed with water, brine and dried over Na2SO4. The filtrate was concentrated under reduced pressure and purified by flash chromatography.

[0486] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-«-L-rhamnopyranosyl-( 1— >2)-3,4-di-t?- benzyl-«-L-rhamnopyranosyl-( l—>3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl)-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (36). The title compound was synthesized from pentasaccharide 28 (450 mg, 0.21 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (cHex / EtOAc 95:5 to 7:3) gave compound 36 (386 mg, 90%) as a crystalline solid.JH NMR (400 MHz, CDC13) 5 (ppm): 7.92-7.88 (m, 4H, Ctf-Ar), 7.82 (s, 1H, Ctf-Ar), 7.57-7.54 (m, 4H, Ctf-Ar), 7.51^7.18 (m, 45H, Ctf-Ar), 6.06-6.96 (m, 1H, H-2AII), 5.43 (ddd, J= 18.8, 3.7, 1.4 Hz, 1H, H-3aAn), 5.37 (t, J= 3.2 Hz, 1H, H-2C), 5.29 (ddd, J= 10.5, 3.4, 1.2 Hz, 1H, H-3bAn), 5.18 (s, 1H, H-1B), 5.15 (br s, 2H, H-1C, H-l A), 5.02-4.86 (m, 10H, H-1E, H-1D, C / ZHPh), 4.74-4.51 (m, 11H, C / ZHPh), 4.39-4.30 (m, 3H, H-laAn, C / ZHPh, H-2D), 4.26-4.05 (m, 9H, H-4D, H- 3C, CZACA, H-lbAii, H-3A, H-6aD, H-6bD, H-3D, H-2B, H-2A), 4.01 (t, J= 9.4 Hz, 1H, H-3E), 3.93 (dd, J= 9.4, 2.6 Hz, 1H, H-3B), 3.88-3.76 (m, 6H, H-5A, H-5B, H-5E, H-5C, H-5D, H- 4E), 3.73 (dd, J= 10.9, 2.5 Hz, 1H, H-6aE), 3.63 (dd, J= 9.7, 3.8 Hz, 1H, H-2E), 3.61 (tJ= 9.3 Hz, 1H, H-4C), 3.54 (tJ= 9.4 Hz, 1H, H-4B), 3.47-3.44 (m, 1H, H-6bE), 3.42 (t, J= 9.2 Hz, 1H, H-4A), 1.36 (d, J= 5.8 Hz, 3H, H-6A), 1.26 (d, J= 6.2 Hz, 3H, H-6B), 1.11 (d, J= 6.2 Hz, 3H, H-6C), 1.05 (s, 9H, C(CH3)3), 0.22 (s, 3H, C#3Si), 0.20 (s, 3H, C#3Si). HRMS (ESI-TOF): m / z [M+NH4]+calcd for CiioHmCU^C^Si 2031.7610; found 2031.7629.

[0487] Allyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?- benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]- 2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1 — >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (37). To title compound was synthesized from pentasaccharide 31 (2.0 g, 1.01 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (TolZEtOAc 95:5 to 8:2) gave compound 37 (1.76 g, 93%) as a crystalline solid. 'H NMR (400 MHz, CDC13) 5 (ppm): 7.47-7.45 (m, 2H, Ctf-Ar), 7.39-7. 18 (m, 44H, Ctf-Ar), 7.01 (d, J = 5.4 Hz, 1H, N / TTCA), 5.94-5.84 (m, 1H, H-2AII), 5.55 (s, 1H, H-7D), 5.31 (ddd, J= 17.2, 3.5, 1.4 Hz, 1H, H-3aAii), 5.25—5.21 (m, 2H, H-3bAn, H-2C), 5.13 (s, 1H, H-l A), 5.08 (d, JID,2D = 7.5 Hz, 1H, H-1D), 4.96 (d, JIB,2B = 1.5 Hz, 1H, H-1B), 4.91 -4.86 (m, 6H, H-1E, H-1C, C / ZHP), 4.83 (d, J= 10.9 Hz, 1H, C / ZHPh), 4.64-4.34 (m, 14H, H-3D, H-3C, H-6aD, C / ZHPh, H-laAn), 4.14-4.07 (m, 2H, H-lbAii, H-3A), 3.99 (s, 2H, CZACA), 3.97 (dd, J= 3.3, 1.5 Hz, 1H, H-2A), 3.95-3.88 (m, 4H, H-5A, H-5C, H-5E, H-2B), 3.85-3.75 (m, 4H, H-3E, H-6bD, H-6aE, H-6bE), 3.72 (t, J= 9.4 Hz, 1H, H-4E), 3.66 (dd, J= 9.6, 2.6 Hz, 1H, H-3B), 3.63-3.50 (m, 3H, H-4D, H-5D, H- 5B), 3.48-3.35 (m, 5H, H-2D, H-4C, H-4A, H-2E, H-4B), 1.33 (d, J= 6.2 Hz, 3H, H-6A), 1.18 (d, J= 6.2 Hz, 3H, H-6B), 0.98 (s, 9H, C(CZA)3), 0.82 (d, J= 6.1 Hz, 3H, H-6C), 0.16 (s, 3H, CJ / 3Si), 0.15 (s, 3H, C / ASi). HRMS (ESI-TOF): m / z [M+NH4]+calcd for C99Hi2iCl4N2O24Si 1889.6827; found 1889.6858.

[0488] Allyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (38). The title compound was synthesized from pentasaccharide 32 (224 mg, 0.112 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (TolZEtOAc 95:5 to 8:2) gave compound 38 (184 mg, 86%) as a crystalline solid. 'H NMR (400 MHz, CDCh) 5 (ppm): 7.86-7.83 (m, 3H, Ctf-Ar), 7.71 (s, 1H, Ctf-Ar), 7.52-7.46 (m, 4H, Ctf-Ar), 7.39-7. 14 (m, 47H, Ctf-Ar), 7.03 (d, J= 6.9 Hz, 1H, WTCA), 5.93-5.83 (m, 1H, H-2AII), 5.57 (s, 1H, H-7D),

[0489] 5.30 (ddd, J= 17.1, 3.8, 1.4 Hz, 1H, H-3aAn), 5.25-5.22 (m, 2H, H-2C, H-3bAn), 5.16 (br s, 1H, H-1A), 5.09 (d, JID,2D = 8.2 Hz, 1H, H-1D), 5.03 (br s, 1H, H-1B), 4.97 (d, J = 10.9 Hz, 1H, C / THPh), 4.92 (d, J= 11.0 Hz, 1H, C / ZHPh), 4.91 (d, J= 11.5 Hz, 1H, C / ZHPh), 4.88-4.83 (m, 5H, H-1E, H-1C, CWHPh), 4.73 (d, J = 10.5 Hz, 1H, CWHPh), 4.68 (d, J= 11.0 Hz, 1H, C / THPh), 4.66 (d, J= 10.5 Hz, 1H, C / ZHPh), 4.60 (d, J= 10.5 Hz, 1H, CWHPh), 4.57-4.54 (m, 5H, H-3D, C / THPh), 4.49 (d, J= 10.9 Hz, 1H, C / ZHPh), 4.41 -4.33 (m, 2H, H-6aD, H-laAii),

[0490] 4.31 (d, J = 12.0 Hz, 1H, C / ZHPh), 4.13-3.93 (m, 10H, H-lbAn, H-3C, H-3E, H-2B, C#2CA, H-2A, H-3A, H-5C, H-5E), 3.85-3.78 (m, 3H, H-5A, H-6bD, H-3B), 3.75 (t, J= 9.7 Hz, H- 4E), 3.71 —3.56 (m, 4H, H-5B, H-4D, H-2E, H-5D), 3.52-3.38 (m, 5H, H-4A, H-6aE, H-2D, H-4B, H-6bE), 3.34 (t, J= 9.4 Hz, 1H, H-4C), 1.28 (d, J= 6.1 Hz, 3H, H-6B), 1.19 (d, J= 6.2 Hz, 3H, H-6A), 0.71 (d, J= 6.1 Hz, 3H, H-6C). HRMS (ESI-TOF): m / z [M+NH4]+calcd for Ci04Hii5C14N2O24 1915.6588; found 1915.6598.

[0491] Synthesis of decasaccharides (lb, 2a and 3a)

[0492] Synthesis of decasaccharide [ABC(E4)D]240 (lb)

[0493] The title compound was obtained as follows:

[0494] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-O-levulinoyl-«-L-rhamnopyranosyl-

[0495] ( 1 — >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1 — >3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-«-L-rhamnopyranosyl-( 1^3)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-

[0496] ( 1 — >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1 -^2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (40). To a solution of acceptor 36a (20 mg, 0.01 mmol, 1.0 equiv.) in anhydrous Toluene (0.4 mL) stirred at rt under Ar, were successively added donor 33 (29 mg, 0.013 mmol, 1.3 equiv.) and activated ground molecular sieves (4A, 59 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -40 °C. After 5 min, TMSOTf (0.5 pL, 0.003 mmol, 0.3 equiv.) was added at this temperature and the reaction mixture was allowed to stir under Ar for 2 h to reach 5 °C. Et3N was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 8:2) to give compound 40 (34 mg, 84%), as a crystalline solid with the presence of corresponding oxazoline (product / oxa: 1 :0.16).JH NMR (400 MHz, CDCh) 5 (ppm): 7.74-7.68 (m, 6H, WTCA, Ctf-Ar), 7.64-7.60 (m, 2H, NH’TCA, Ctf-Ar), 7.41 —7.36 (m, 3H, Ctf-Ar), 7.32-7. 17 (m, 30H, Ctf-Ar), 7.16-6.90 (m, 50H, Ctf-Ar), 5.84-5.74 (m, 1H, H-2AII), 5.33 (br s, 1H, H-1C), 5.23 (t, J= 2.8 Hz, 1H, H-2C), 5.22— 5.16 (m, 2H, H-3aAn, H- 1D’), 5.13 (t, J= 3.4 Hz, 1H, H-2A’), 5. 12-5.07 (m, 2H, H-3bAn, CWHPh), 5.04 (br s, 1H, H- 1B), 4.97 (br s, 1H, H-1B’), 4.92 (br s, 1H, H-1C’), 4.89 (br s, 1H, H-1A), 4.84-4.64 (m, 16H, H-1A’, H-1E’, H-1D, H-1E, CWHPh), 4.62-4.39 (m, 18H, C / ZHPh), 4.36-4.21 (m, 5H, CWHPh), 4.20-3.93 (m, 15H, H-laAn, H-3D’, H-4D’, H-2D, H-2D’, H-3C, H-3A’, H-3C’, H- IbAH, C#2CA, C# ’2CA, H-5D, H-5D’), 3.93-3.78 (m, 8H, H-4D, H-2B’, H-3D, H6aD, H-3E, H- 2B, H-3E’, CHHPh), 3.76 (br s, 1H, H-2A), 3.74-3.28 (m, 24H, H-5A’, H-3B’, H-3B, H-3A, H-5B, H-5C, H-5A, H-5B’, H-5C’, H-4E, H-4E’, H-6bD, H-5E, H-5E’, H-6aD’, H-6bD’, H6aE, H-4A, H-2E’, H-2E, H-4C’, H-4C, H6aE’, H-4B’), 3.25-3.22 (m, 1H, H-6bE), 3.16 (t, J= 8.9 Hz, 1H, H-4A’), 3.13 (t, J= 9.3 Hz, 1H, H-4B), 2.98 (d, J= 10.7 Hz, 1H, H-6bE’), 2.66-2.52 (m, 4H, 2 x C#2Lev), 2.08 (s, 3H, C / f3Lev), 1.14 (d, J= 6.4 Hz, 3H, H-6B’*), 1.09 (d, J= 6.4 Hz, 3H, H-6B), 1.04 (d, J= 6.5 Hz, 3H, H-6A*), 0.98 (d, J= 6.1 Hz, 3H, H-6A’*), 0.93 (d, J= 5.9 Hz, 3H, H-6C), 0.82 (d, J= 6.0 Hz, 3H, H-6C’*), 0.80 (s, 9H, C(C / f3)3), 0.00 (s, 3H, mSi), -0.05 (s, 3H, C#3Si).

[0497] Synthesis of decasaccharide [AB(E)CD]i 41 (2a)

[0498] The title compound was obtained as follows:

[0499] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl- (1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O- benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O-benzyl-3-O- terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-( 1— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (41). To a solution of acceptor 37 (200 mg, 0.107 mmol, 1.0 equiv.) in anhydrous Toluene (4 mL), were successively added donor 34 (288 mg, 0.133 mmol, 1.25 equiv.) and activated ground molecular sieves (4A, 140 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -30 °C. After 5 min, TBSOTf (5.0 pL, 0.021 mmol, 0.2 equiv.) was added at this temperature and the reaction mixture was allowed to stir under Ar for 1 h from -40 to 0 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (cHex / EtOAc 95:5 to 8:2) to give compound 41 (379 mg, 93%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C2ooH242Cl8N4049Si2 1909.6802; found 1909.6803.

[0500] Synthesis of decasaccharide [(E)ABCDJi 42 (3a)

[0501] The title compound was obtained as follows:

[0502] Allyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1 — >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(1^2)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (42). To a solution of acceptor 38 (25 mg, 0.013 mmol, 1.0 equiv.) in anhydrous Toluene (0.5 mL), were successively added donor 35 (35 mg, 0.016 mmol, 1.3 equiv.) and activated ground molecular sieves (4A, 13 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -40 °C. After 5 min, TBSOTf (0.6 pL, 0.003 mmol, 0.2 equiv.) was added at this temperature and the reaction mixture was allowed to stir under Ar for 1 h from -40 to -15 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 8:2) to give compound 42 (43 mg, 86%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C210H230CI8N4O49 1935.6563; found 1935.6564.

[0503] Synthesis of decasaccharide donors and acceptors (lb, 2a and 3a)

[0504] The title compounds were obtained as follows:

[0505] 4-O-Benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl-( 1— >2)-3,4- di-f?-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f>- benzyl-a-D-glucopyranosyl-(l— >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido-a / p-D- glucopyranosyl (A-phenyl)trifluoroacetimidate (44). The title compound was synthesized from decasaccharide 40 (312 mg, 0.077 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (cHex / EtOAc 95:5 to 7:3 + TEA) gave compound 44 (216 mg, 80%, over 2 steps) as a crystalline solid. FIRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C228H254Cl8F3N5O49Si 2105.2378 found 2105.2379.

[0506] Allyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?- benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]- 2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 —>2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- f>-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (45). The title compound was synthesized from decasaccharide 41 (379 mg, 0.100 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2) gave compound 45 (315 mg, 85%) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for Ci95H236Cl8N4O47Si21860.6618; found 1860.6636.

[0507] Allyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (46). The title compound was synthesized from decasaccharide 42 (158 mg, 0.041 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2) gave compound 46 (135 mg, 88%) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C205H224Cl8N4O47 1886.6379; found 1886.6392.

[0508] Synthesis of pentadecasaccharides (lb, 2a and 3a)

[0509] Synthesis of pentadecasaccharide [ABC(E)D]3 47 (la / lb)

[0510] The title compound was obtained as follows:

[0511] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-O-levulinoyl-«-L-rhamnopyranosyl-

[0512] ( 1 — >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1 —>3)-2-O-chloroacetyl-4-O-(2- naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D- I l l glucopyranosyl-(l—>4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl- (1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(1^2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O- benzyl-a-D-glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (47). To a solution of donor 44 (65 mg, 0.016 mmol, 1.0 equiv.) in anhydrous Toluene (0.9 mL) stirred at rt under Ar, were successively added acceptor 36a (37 mg, 0.019 mmol, 1.2 equiv.) and activated ground molecular sieves (4A, 37 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -30 °C. After 5 min, TBSOTf (0.5 pL, 0.003 mmol, 0.3 equiv.) was added at this temperature and the reaction mixture was allowed to stir under Ar for 2 h from to reach 0 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (TolZEtOAc 95:5 to 8:2) to give compound 47 (41 mg, 42%), as a crystalline solid with the presence of oxazoline trace. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C33iH367Cli2N5O75Si 3007.0635 found 3007.0463.

[0513] Synthesis of pentadecasaccharide [AB(E)CD]3 48 (2a)

[0514] The title compound was obtained as follows: Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-CMevulinoyl-«-L-rhaninopyranosyl- (1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O- benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O-benzyl-3-O- terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 —>2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (48). To a solution of donor 34 (314 mg, 0.085 mmol, 1.0 equiv.) in anhydrous Toluene (3 mL) stirred at rt under Ar, were successively added acceptor 45 (215 mg, 0.102 mmol, 1.2 equiv.) and activated ground molecular sieves (4A, 107 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -30 °C. After 5 min, TBSOTf (3.0 pL, 0.013 mmol, 0.15 equiv.) was added at this temperature and the reaction mixture was allowed to stir under Ar for 2 h from -30 to 10 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (50 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 48 (443 mg, 93%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C296H353Cli2N5O72Si3 2817.4817; found 2817.9976.

[0515] Synthesis of pentadecasaccharide [(E)ABCD]3 49 (3a)

[0516] The title compound was obtained as follows:

[0517]

[0518] Allyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1 — >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l—>3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranosyl-(l— >2)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1— >3)]-4-O-benzyl-«- L-rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (49). To a solution of acceptor 46 (25 mg, 0.007 mmol, 1.0 equiv.) in anhydrous Toluene (0.3 mL), were successively added donor 35 (26 mg, 0.012 mmol, 1.8 equiv.) and activated ground molecular sieves (4A, 13 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -50 °C. After 5 min, TMSOTf (1.0 pL, 0.006 mmol, 0.8 equiv.) was added at this temperature and the reaction mixture was allowed to stir under Ar for 5 h from to reach 10 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 49 (35 mg, 88%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C311H335CI12N5O72 2855.4493; found 2856.4549.

[0519] Synthesis of pentadecasaccharides bearing an azidoalkyl aglycon Synthesis of azidoethyl- or azidopropyl-equipped pentasaccharides

[0520] The title compounds were obtained as follows:

[0521] 3-Azidopropyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O- benzyl-a-D-glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (50). To a solution of donor 33 (273 mg, 0.122 mmol, 1.0 equiv.) in anhydrous Toluene ( 2.4 mL), was added activated ground molecular sieves (4A, 547 mg). The mixture was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -65 °C. After 5 min, TMSOTf (4 pL, 0.024 mmol, 0.2 equiv.) was added. After 10 min, azidopropanol (17 pL, 0.183 mmol, 1.5 equiv. dissolved in 0.6 mL of anhydrous Toluene) was added to the suspension and the reaction mixture was allowed to stir under Ar for 1 h from -65 to 0 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (50 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 8:2) to give compound 50 (197 mg, 75%), as a crystalline solid.JH NMR (400 MHz, CDCh) 5 (ppm): 7.85—7.81 (m, 3H, Ctf-Ar), 7.76-7.74 (m, 2H, WTCA, Ctf-Ar), 7.51 -7.48 (m, 2H, Ctf-Ar), 7.41^7.10 (m, 40H, Ctf-Ar), 5.26 (dd, J= 3.4, 2.0 Hz, 1H, H-2A), 5.22 (dd, J= 3.5, 1.9 Hz, 1H, H-2C), 5.09 (d, JIB,2B = 1.3 HZ, 1H, H-1B), 5.03 (d, Jic,2c = 1.4 Hz, 1H, H-1C), 4.91 —4.77 (m, 9H, H-1A, H-1E, C / ZHPh), 4.72 (d, JID,2D = 2.3 Hz, 1H, H-1D), 4.67-4.48 (m, 9H, C / ZHPh), 4.44 (d, J= 10.5 Hz, 1H, C / ZHPh), 4.26 (d, J= 12.0 Hz, 1H, C / ZHPh), 4.20-4.06 (m, 6H, H-2D, H-3A, CH2CA, H-5D, H-3C), 3.99 (br s, 2H, H-3D, H-4D), 3.94 (t, J= 2.9 Hz, 1H, H-2B), 3.93-3.84 (m, 3H, H-6aD, H-3E, C#Link), 3.82 (dd, J= 9.4, 2.6 Hz, 1H, H-3B), 3.79-3.66 (m, 6H, H-5A, H-5E, H-5B, H-5C, H-6bD, H-4E), 3.64 (dd, J = 10.8, 2.7 Hz, 1H, H-6aE), 3.58-3.36 (m, 7H, C#Link, H-2E, H-4C, H-4B, C^Link, H-6bE), 3.31 (t, J= 9.2 Hz, 1H, H-4A), 2.76-2.65 (m, 4H, 2 x CH2Lev), 2.20 1.27 (d, J= 6.1 Hz, 3H, H-6B), 1.17 (d, J= 6.2 Hz, 3H, H-6C), 1.02 (d, J= 6.2 Hz, 3H, H-6A), 0.92 (s, 9H, C(C#3)3), 0.14 (s, 3H, C#3Si), 0.09 (s, 3H, C#3Si). HRMS (ESI-TOF): m / z [M+NH4]+calcd for CnsHnsCUNsCheSi 2172.8148; found 2172.8194.

[0522] 2-Azidoethyl 4-O-benzyl-3-O-terCbutyldimethylsilyl-2-CMevulinoyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f>- benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6- O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (51). To a solution of PTFA donor 34 (220 mg, 0.105 mmol, 1.0 equiv.) in anhydrous DCE ( 2.4 mL), was added activated ground molecular sieves (4A, 440 mg). The mixture was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -30 °C. After 5 min, TMSOTf (2 pL, 0.010 mmol, 0.1 equiv.) was added. After 10 min, acceptor azidoethanol (12 pL, 0.157 mmol, 1.5 equiv. dissolved in 1.3 mL of anhydrous DCE) was added to the suspension and the reaction mixture was allowed to stir under Ar for 2 h 30 from -15 °C to rt. Et3N was added. The suspension was filtered over Celite, rinsed with DCM (50 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (Tol / EtOAc 95:5 to 85: 15) to give compound 51 (170 mg, 81%), as a crystalline solid. 'H NMR (400 MHz, CDC13) 5 (ppm): 7.47-7.45 (m, 2H, Ctf-Ar), 7.40-7.39 (m, 4H, Ctf-Ar), 7.36-7.18 (m, 43H, Ctf-Ar), 5.55 (s, 1H, H-7D), 5.29 (dd, J= 3.4, 2.0 Hz, 1H, H-2A), 5.22 (t, J= 3.4 Hz, 1H, H-2C), 5.14 (d, JID,2D = 7.8 Hz, 1H, H-1D), 5.05 (s, 1H, H-l A), 4.95 (s, 1H, H-1B), 4.94 (d, J= 10.9 Hz, 1H, C / ZHPh), 4.93-4.84 (m, 6H, H-1E, H-1C, C / ZHPh), 4.81 (d, J= 10.9 Hz, 1H, C / ZHPh), 4.65-4.48 (m, 11H, C / ZHPh, H-3D), 4.40-4.36 (m, 3H, H-6aD, C / ZHPh), 4.21 (dd, J = 9.2, 3.1 Hz, 1H, H- 3A), 4.05-3.87 (m, 8H, H-3C, CZAink, CZACA, H-5A, H-5C, H-5E, H-2B), 3.84-3.64 (m, 7H, H-3E, H-6bD, H-6aE, H-6bE, CfAink, H-3B, H-4E), 3.62-3.36 (m, 10H, H-4D, H-5D, H-5B, C#2Link, H-2D, H-4C, H-4B, H-4A, H-2E), 2.71 -2.54 (m, 4H, 2 x CH2L^ 2.13 (s, 3H, CA3Lev), 1.33 (d, J= 6.2 Hz, 3H, H-6A), 1.18 (d, J= 6.2 Hz, 3H, H-6B), 0.94 (s, 9H, C(C#3)3), 0.83 (d, J= 6.1 Hz, 3H, H-6C), 0.16 (s, 3H, C / ASi), 0.13 (s, 3H, C / ASi). HRMS (ESI-TOF): m / z [M+NH4]+calcd for Cio3Hi26Cl4N5026Si 2016.7209; found 2016.7186.

[0523] 3-Azidopropyl |2.3.4.6-tetr:i-O-benzyl-( / -l)-glucopyranosyl-(1^3)|-4-O-benzyl-2-O- levulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L-rhamnopyranosyl-(l— >3)-2- O-chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene- 2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (52). To a solution of PTFA donor 35 (100 mg, 0.047 mmol, 1.0 equiv.) in anhydrous Toluene (1 mL) was added activated ground molecular sieves (4A, 200 mg). The mixture was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -60 °C and TMSOTf (1.0 pL, 0.006 mmol, 0.125 equiv.) was added. After 10 min, azidopropanol (7 pL, 0.07 mmol, 1.5 equiv. dissolved in 1 mL of anhydrous Toluene) was added to the previous solution and the mixture was stirred from -60 to -40°C for 2 h. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (cHex / EtOAc 95:5 to 6:4) to give compound 52 (82 mg, 85%), as a crystalline solid. 'HNMR (400 MHz, CDC13) 5 (ppm): 7.87-7.84 (m, 3H, Ctf-Ar), 7.71 (s, 1H, Ctf-Ar), 7.53-7.48 (m, 4H, Ctf-Ar), 7.42-7.09 (m, 37H, Ctf-Ar), 7.05 (d, J = 7.2 Hz, 1H, WTCA), 5.94-5.84 (m, 1H, H-2AII), 5.57 (s, 1H, H-7D), 5.56 (t, J= 3.3 Hz, H-2A), 5.26-5.23 (m, 2H, H-1E, H-2C), 5.06—5.01 (m, 3H, H-1D, H-1B, C / ZHPh), 4.99 (d, JIA,2A = 1.3 Hz, 1H, H-1A), 4.96-4.87 (m, 5H, H-1C, C / ZHPh), 4.82 (d, J= 11.4 Hz, 1H, C / ZHPh), 4.78 (d, J= 11.9 Hz, 1H, C / ZHPh), 4.7869 (d, J = 11.9 Hz, 1H, C / ZHPh), 4.78 (d, J = 11.1 Hz, 1H, C / ZHPh), 4.63-4.49 (m, 8H, H-3D, C / ZHPh), 4.41 (dd, J= 10.4, 4.4 Hz, 1H, H-6aD), 4.36 (d, J= 12.1 Hz, 1H, C / ZHPh), 4.25 (dd, J= 9.7, 3.1 Hz, 1H, H-3A), 4.14—3.95 (m, 8H, H-3E, H-3C, H-5E, C#2CA, H-5C, C#Link, H-2B), 3.88-3.79 (m, 4H, H-5A, H-6bD, H-4E, H-3B), 4.25 (dd, J = 9.7, 3.1 Hz, 1H, H-3A), 3.70-3.49 (m, 10H, H-5B, H-6aE, C#Link, H-4D, H-2E, H-5D, H-6bE, H-4A, H-2D, H-4B), 3.42 (td, J = 6.7, 1.1 Hz, 2H, C^Link), 3.33 (t, J = 9.5 Hz, H-4C), 2.60-2.34 (m, 4H, 2 x C#2Lev), 2.05 (s, 3H, C#3Lev), 1.89^1.83 (m, 2H, Cftiik), 1.26 (d, J= 6.2 Hz, 3H, H-6B), 1.20 (d, J= 6.2 Hz, 3H, H-6A), 0.71 (d, J= 6.1 Hz, 3H, H-6C). HRMS (ESI-TOF): m / z [M+NH4]+calcd for C109H122CI4N5O26 2056.7127; found 2056.7110.

[0524] Synthesis of azidopropyl- or azidoethyl-equipped decasaccharides

[0525] Starting from pentasaccharides

[0526]

[0527] 3-Azidopropyl 4-O-benzyl-3-O-ter?-butyldimethylsilyl-2-O-levulinoyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (53). The compound 50 (197 mg, 0.091 mmol, 1.0 equiv.) was dissolved in a mixture of water / Py (1 : 1.3, 6.4 mL). The suspension was stirred at 55 °C overnight. After evaporation and coevaporation three times with toluene under reduced pressure, the obtained crude was dissolved in a mixture of Ac2O / Py (1 : 1, 5.5 mL). DMAP (2 mg, 0.02 mmol, 0.2 equiv.) was added and the suspension was allowed to run at overnight at rt under Ar. Solvents were concentrated under reduced pressure and co-evaporated with toluene (3 x 2 mL). The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 75: 15) to give compound 54 (180 mg, 93%, over 2 steps), as a crystalline yellow solid.JH NMR (400 MHz, CDCh) 5 (ppm): 7.71 —7.64 (m, 4H, Ctf-Ar), 7.61 (s, 1H, Ctf-Ar), 7.37-7.33 (m, 2H, Ctf-Ar), 7.27 (dd, J= 8.3, 1.5 Hz, 1H, Ctf-Ar), 7.24-6.97 (m, 46H, Ctf-Ar), 5.12 (dd, J= 3.4, 2.0 Hz, 1H, H-2A), 5.04 (dd, J= 3.6, 1.8 Hz, 1H, H-2C), 4.94 (d, JIB,2B = 1.3 Hz, 1H, H-1B), 4.88 (d, . / l c.2c = 1.3 Hz, 1H, H-1C), 4.78 (d, J = 11.0 Hz, 1H, C / ZHPh), 4.77-4.70 (m, 5H, H-1A, C / ZHPh),

[0528] 4.67-4.63 (m, 3H, H-1E, C / ZHPh), 4.58 (d, JID,2D = 2.2 Hz, 1H, H-1D), 4.53-4.29 (m, 10H, C / ZHPh), 4.11 (d, J= 12.0 Hz, 1H, C / ZHPh), 4.08 (d, J= 8.0 Hz, 1H, H-2D), 4.01 (dd, J= 9.0, 3.2 Hz, 1H, H-3A), 3.99-3.96 (m, 1H, H-5D), 3.92 (dd, J= 9.3, 3.3 Hz, 1H, H-3C), 3.85-3.72 (m, 6H, H-3D, H-4D, H-2B, H-6aD, H-3E, C#Link), 3.69 (dd, J = 9.3, 2.7 Hz, 1H, H-3B),

[0529] 3.67-3.53 (m, 6H, H-5A, H-5E, H-5B, H-6bD, H-5C, H-4E), 3.50 (dd, J = 10.9, 2.7 Hz, 1H, H-6aE), 3.43-3.27 (m, 6H, H-2E, C#Link, H-4C, H-4B, C^Link), 3.23 (dd, J = 10.9, 1.4 Hz, 1H, H-6bE), 3.17 (t, J= 9.3 Hz, 1H, H-4A), 2.62—2.51 (m, 4H, 2 x CH2L^ 2.06 (s, 3H, Cftkv), 2.03 (s, 3H, OTAC), 1.78^1.68 (m, 2H, C^Link), 1.14 (d, J= 6.2 Hz, 3H, H-6B), 1.07 (d, J= 6.2 Hz, 3H, H-6C), 0.89 (d, J= 6.2 Hz, 3H, H-6A), 0.79 (s, 9H, 0.00 (s, 3H, C#3Si),

[0530] -0.04 (s, 3H, CH3Si). HRMS (ESI-TOF): m / z |M+NH4| calcd for C104H119CI3N5O24 1926.7305 found 1926.7313.

[0531] 3-Azidopropyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1— >3)]-4-O-benzyl-2-O- levulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L-rhamnopyranosyl-(l— >3)-2- O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-( 1 — >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (54). The compound 52 (840 mg, 0.411 mmol, 1.0 equiv.) was dissolved in a mixture of water / Py (1 : 1, 24 mL). The suspension was stirred at 55 °C overnight. After evaporation and coevaporation three times with toluene under reduced pressure, the obtained crude was dissolved in a mixture of Ac2O / Py (1 : 1, 38 mL). DMAP (23 mg, 0.206 mmol, 0.5 equiv.) was added and the suspension was allowed to run at rt for 4 h under Ar. Following addition of DCM (100 mL), the solution was washed with an aqueous solution of CuSCh (3 x 50 mL), water (50 mL) and brine (50 mL), dried over Na2SO4 and concentrated to dryness. The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 7:3) to give compound 54 (713 mg, 86%, over 2 steps), as a crystalline yellow solid. 'HNMR (400 MHz, CDCI3) 5 (ppm): 7.87-7.83 (m, 3H, C / 7-Ar), 7.70 (s, 1H, C / 7-Ar), 7.53-7.46 (m, 5H, C77-Ar), 7.41^7.11 (m, 47H, C / 7-Ar), 7.08 (d, J= 6.7 Hz, 1H, WTCA), 5.57 (s, 1H, H- 7D), 5.53 (t, J= 3.2 Hz, H-2A), 5.24 (d, JIE,2E = 3.2 Hz, 1H, H-1E), 5.17 (dd, J= 3.5, 1.8 Hz, 1H, H-2C), 5.08 (d, JID,2D = 8.2 Hz, 1H, H-1D), 5.04-4.99 (m, 2H, H-1B, C / ZHPh), 4.97 (d, JIA,2A = 1.5 Hz, 1H, H-1A), 4.94-4.79 (m, 7H, H-1C, C / ZHPh), 4.77 (d, J = 12.1 Hz, 1H, Cf / HPh), 4.68-4.48 (m, 11H, H-3D, C / ZHPh), 4.39 (dd, J= 10.6, 4.5 Hz, 1H, H-6aD), 4.34 (d, J= 12.1 Hz, 1H, Cf / HPh), 4.23 (dd, J= 9.7, 3.0 Hz, 1H, H-3A), 4.10 (t, J= 9.4 Hz, 1H, H-3E), 4.07-3.94 (m, 7H, H-5E, H-3C, H-5C, CH2CA, H-2B, C#Link), 3.87-3.77 (m, 4H, H-5A, H- 3B, H-4E, H-6bD), 3.73-3.43 (m, 10H, H-5B, H-6aE, C#Link, H-4D, H-2E, H-5D, H-6bE, H- 4A, H-4B, H-2D), 3.39 (td, J= 6.9, 1.4 Hz, 2H, C#2Link), 3.34 (t, J= 9.5 Hz, H-4C), 2.59-2.33 (m, 4H, 2 x CZ / 2Lev), 2.07 (s, 3H, C / AAC), 2.06 (s, 3H, C / AKV), 1.89^1.83 (m, 2H, CZAkink), 1.26 (d, J= 6.2 Hz, 3H, H-6B), 1.20 (d, J= 6.2 Hz, 3H, H-6A), 0.75 (d, J= 6.1 Hz, 3H, H-6C). HRMS (ESI-TOF): m / z |M+NH4| calcd for C109H123CI3N5O262022.7516; found 2022.7542.

[0532] 3-Azidopropyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-«-L-rhamnopyranosyl-( 1— >2)-3,4- di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (55). The title compound was synthesized from pentasaccharide 53 (108 mg, 0.051 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (Tol / EtOAc 95:5 to 85: 15) gave compound 55 (88 mg, 85%) as a crystalline solid. 'H NMR (400 MHz, CDC13) 5 (ppm): 7.85-7.74 (m, 5H, N / TTCA, C / f-Ar), 7.52-7.47 (m, 2H, C / f-Ar), 7.42 (dd, J = 8.8, 1.6 Hz, 1H, C / f-Ar), 7.38^7.11 (m, 39H, C / f-Ar), 5.18 (dd, J= 3.5, 1.8 Hz, 1H, H-2C), 5.08 (d, JIB,2B = 1.4 Hz, 1H, H-1B), 5.06 (d, JIA,2A = 1.3 Hz, 1H, H-1A), 5.03 (d, Jic,zc = 1.5 Hz, 1H, H-1C), 4.94 (d, J= 11.4 Hz, 1H, C / ZHPh), 4.89 (d, J= 10.8 Hz, 1H, C / ZHPh), 4.87 (d, J = 11.1 Hz, 1H, C / ZHPh), 4.84 (d, J = 10.8 Hz, 1H, C / ZHPh), 4.81 —4.77 (m, 4H, H-1E, C / ZHPh), 4.73 (d, JID,2D = 2.1 Hz, 1H, H-1D), 4.67 (d, J= 11.9 Hz, 1H, C / ZHPh), 4.64 (d, J = 11.4 Hz, 1H, C / ZHPh), 4.60 (d, J= 12.7 Hz, 1H, C / ZHPh), 4.54 (d, J= 11.3 Hz, 1H, C / ZHPh), 4.53 (d, J = 11.7 Hz, 1H, C / ZHPh), 4.52-4.46 (m, 5H, C / ZHPh), 4.45 (d, J = 10.7 Hz, 1H, C / ZHPh), 4.26 (d, J= 12.1 Hz, 1H, C / ZHPh), 4.23-4.21 (m, 1H, H-2D), 4.14-4.04 (m, 4H, H- 5D, H-3C, H-2B), 3.99 (br s, 2H, H-3D, H-4D), 3.96 (t, J= 3.7 Hz, 1H, H-2A), 3.94-3.67 (m, 10H, H-6aD, H-3E, C#Link, H-3B, H-5A, H-5E, H-5B, H-6bD, H-5C, H-4E), 3.64 (dd, J= 10.8, 2.7 Hz, 1H, H-6aE), 3.57-3.36 (m, 7H, H-2E, C#Link, H-4C, H-4B, CWink, H-6bE), 3.34 (t, J = 9.2 Hz, 1H, H-4A), 2.17 (s, 3H, C#3Ac), 1.90^1.83 (m, 2H, C#2Link), 1.28 (d, J= 6.2 Hz, 3H, H-6B), 1.21 (d, J= 6.2 Hz, 3H, H-6C), 1.06 (d, J= 6.3 Hz, 3H, H-6A), 0.97 (s, 9H, C(C#3)3), 0.15 (s, 3H, C#3Si), 0.13 (s, 3H, C#3Si). HRMS (ESI-TOF): m / z [M+NH4]+calcd for CnoHi33Cl3N5024Si 2040.8170; found 2040.8197.

[0533] 2-Azidoethyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4- di-f>-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-

[0534] ( 1 — >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1 — >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (56). The title compound was synthesized from pentasaccharide 51 (133 mg, 0.066 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (TolZEtOAc 95:5 to 75: 15) gave compound 56 (120 mg, 95%) as a yellow solid. HRMS (ESI-TOF): m / z [M+NH4]+calcd for C98Hi2oCl4N5024Si 1918.6841; found 1918.6846.

[0535] 3-Azidopropyl |2.3.4.6-tetr:i-O-benzyl-( / -l)-glucopyranosyl-(1^3)|-4-O-benzyl-«-l - rhamnopyranosyl-( 1— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (57). The title compound was synthesized from pentasaccharide 54 (37 mg, 0.018 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (TolZEtOAc 95:5 to 8:2) gave compound 57 (30 mg, 87%) as a crystalline yellow solid.XH NMR (400 MHz, CDC13) 5 (ppm): 7.87-7.84 (m, 3H, Ctf-Ar), 7.72 (s, 1H, Ctf-Ar), 7.53-7.47 (m, 4H, Ctf-Ar), 7.40— 7. 14 (m, 41H, Ctf-Ar), 7.09 (d, J = 7.3 Hz, 1H, NATCA), 5.57 (s, 1H, H-7D), 5.18 (dd, J= 3.6, 1.8 Hz, H-2C), 5.16 (s, 1H, H-1A), 5.06 (d, JID,2D = 8.2 Hz, H-1D), 5.02 (s, 1H, H-1B), 4.97 (d, J = 11.0 Hz, 1H, C / ZHPh), 4.94—4.81 (m, 7H, H-1E, H-1C, C / ZHPh), 4.76-4.45 (m, 11H, H-3D, C / ZHPh), 4.39 (dd, J= 10.4, 4.6 Hz, 1H, H-6aD), 4.32 (d, J= 12.2 Hz, I H, CT / HPh), 4.08-3.94 (m, 8H, H-2B, H-3C, H-3E, H-2A, H-3A, H-5C, C#Link, H-5E), 3.87-3.55 (m, 9H, H-5A, H- 3B, H-6bD, H-4E, H-5B, H-4D, C#Link, H-2E, H-5D), 3.53—3.33 (m, 8H, H-6aE, H-4A, H-2D, H-4B, H-6bE, C#2Link, H-4C), 2.07 (s, 3H, C#3Ac), 1.89^1.83 (m, 2H, C#2Link), 1.28 (d, J= 6.3 Hz, 3H, H-6B), 1.21 (d, J= 6.2 Hz, 3H, H-6A), 0.75 (d, J= 6.1 Hz, 3H, H-6C). HRMS (ESI-TOF): m / z [M+NH4]+calcd for C104H117CI3N5O24 1924.7149; found 1924.7144.

[0536] 2-Azidoethyl 4-O-benzyl-3-O-ter?-butyldimethylsilyl-2-O-levulinoyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f>- benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6- O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O-benzyl-3- O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (59). To a solution of acceptor 56 (120 mg, 0.063 mmol, 1.0 equiv.) in anhydrous Toluene (3 mL), were successively added donor 34 (159 mg, 0.076 mmol, 1.2 equiv.) and activated ground molecular sieves (4A, 80 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -35 °C. After 5 min, TBSOTf (3.0 pL, 0.013 mmol, 0.2 equiv.) was added at this temperature and the reaction mixture was allowed to stir under Ar for 6 h from -30 °C to rt. Et3N was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (TolZEtOAc 95:5 to 8:2) to give compound 59 (204 mg, 84%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for Ci99H24iCl8N7O49Si21924.1809; found 1924.1759.

[0537] 3-Azidopropyl [2,3,4,6-tetra-f>-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-2-O- levulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L-rhamnopyranosyl-(l— >3)-2- f>-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-

[0538] ( 1 — >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (60). To a solution of acceptor 57 (255 mg, 0.134 mmol, 1.0 equiv.) in anhydrous Toluene (5.3 mL), were successively added donor 86 (350 mg, 0.165 mmol, 1.25 equiv.) and activated ground molecular sieves (4A, 1.02 g). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -42 °C. After 5 min, TMSOTf (7.0 pL, 0.040 mmol, 0.3 equiv.) was added at this temperature and the reaction mixture was allowed to stir under Ar for 1 h from -40 to 0 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (40 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 60 (580 mg, 82%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for Ci99H24iCl8N7O49Si21924.1809; found 1924.1759.

[0539] Starting from decasaccharides

[0540] 4-O-Benzyl-3-O-tert-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4- di-f>-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl- (1— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O-rert-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido-a / / ?-D-glucopyranosyl (N- phenyl)trifluoroacetimidate (61). The title compound was synthesized from decasaccharide 41 (250 mg, 0.066 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2 + TEA) gave compound 61 (221 mg, 88%, over 2 steps) as a crystalline solid. FIRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C205H242Cl8F3N5O49Si2 1975.1793; found 1975.1852.

[0541] [2,3,4,6-Tetra-O-benzyl-a-D-glucopyranosyl-( 1— >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido-a / / ?-D- glucopyranosyl (A-phenyl)trifluoroacetimidate (62). The title compound was synthesized from decaaccharide 42 (247 mg, 0.064 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2 + TEA) gave compound 62 (211 mg, 88%, over 2 steps) as a crystalline solid. FIRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C215H230CI8F3N5O492001.1554; found 2001.1571.

[0542] 3-Azidopropyl [2,3,4,6-tetra-f>-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-2-O- levulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L-rhamnopyranosyl-(l— >3)-2- O-chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-

[0543] 2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (63). To a solution of donor 62 (208 mg, 0.052 mmol, 1.0 equiv.) in anhydrous DCE (1.6 mL), was added activated ground molecular sieves (4A, 416 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -25 °C after which TMSOTf (1.0 pL, 0.005 mmol, 0.1 equiv.) was added. After 10 min, azidopropanol (7 pL, 0.079 mmol, 1.5 equiv., dissolved in 1.6 mL of anhydrous DCE) was added and the mixture was allowed to stir from -20 °C to rt for 5 h. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (40 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (Tol / EtOAc 95:5 to 8:2) to give compound 63 (154 mg, 77%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C210H231CI8N7O49 1957.1648; found 1957.1672.

[0544] 3-Azidopropyl 4-O-beiizyl-3-O- / c / 7-biityldiniethylsilyl-2-O-leviilinoyl-<z-l - rhamnopyranosyl-(l—>2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l—>3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f>- benzyl-a-D-glucopyranosyl-(l— >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«- L-rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f?-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (64). To a solution of donor 44 (140 mg, 0.034 mmol, 1.0 equiv.) in anhydrous Toluene (1.3 mL), was added activated ground molecular sieves (4A, 281 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -65 °C after which TMSOTf (2.0 pL, 0.010 mmol, 0.3 equiv.) was added. After 10 min, azidopropanol (5 pL, 0.057 mmol, 1.7 equiv., dissolved in 0.2 mL of anhydrous Toluene) was added and the mixture was allowed to stir from -20 °C to rt for 5 h. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (40 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 8:2) to give compound 64 (104 mg, 75%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C223H255Cl8N7O49Si 2061.7488 found 2061.7553.

[0545] Synthesis of azidopropyl-equipped pentadecasaccharide 67 (la / lb)

[0546] Starting from pentadecasaccharide 47

[0547] 4-O-Benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl-( 1— >2)-3,4- di-f?-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f>- benzyl-a-D-glucopyranosyl-(l— >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«- L-rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl (A-phenyl)trifluoroacetimidate (66). The title compound was synthesized from pentadecasaccharide 47 (305 mg, 0.051 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2 + TEA) gave compound 66 (164 mg, 51%, over 2 steps) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C336H367Cli2F3N6O72Si 3072.5627 found 3072.5144.

[0548] 3-Azidopropyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-CMevulinoyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O- benzyl-a-D-glucopyranosyl-(l— >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«- L-rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(1^2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O- benzyl-a-D-glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (67). To a solution of donor 66 (163 mg, 0.027 mmol, 1.0 equiv.) in anhydrous Toluene (1.1 mL) was added activated ground molecular sieves (4A, 326 mg). The mixture was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -65 °C. After 5 min, TMSOTf (1.0 pL, 0.008 mmol, 0.3 equiv.) was added. After 10 min, azidopropanol (4.0 pL, 0.040 mmol, 1.5 equiv. dissolved in 0.1 mL of anhydrous Toluene) was added to the suspension and the reaction mixture was allowed to stir under Ar for 1 h from -65 to 10 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 85: 15) to give compound 67 (112 mg, 69%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C33iH368Cli2N8O72Si 3028.5720 found 3028.5838.

[0549] Synthesis of azidoethyl-equipped pentadecasaccharide 70 (2a) Starting from azidoethyl-equipped pentasaccharide 51

[0550]

[0551] 2-Azidoethyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4- di-O-benzyl-«-L-rhamnopyranosyl-(1^3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl- (1— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 —>2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (69). The title compound was synthesized from decasaccharide 63 (202 mg, 0.053 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2) gave compound 69 (160 mg, 81%) as a yellow solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for Ci94H235Cl8N7O47Si21875.1625; found 1875.1538.

[0552] 2-Azidoethyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f>- benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6- O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O-benzyl-3- O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 —>2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- f>-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (70). To a solution of acceptor 69 (160 mg, 0.043 mmol, 1.0 equiv.) in anhydrous Toluene (3 mL) stirred at rt under Ar, were successively added donor 34 (109 mg, 0.052 mmol, 1.2 equiv.) and activated ground molecular sieves (4A, 160 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -35 °C. After 5 min, TBSOTf (2.0 pL, 0.009 mmol, 0.2 equiv.) was added at this temperature and the reaction mixture was allowed to stir under Ar for 2 h from -30 to 10 °C. EttN was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (TolZEtOAc 95:5 to 8:2) to give compound 70 (212 mg, 87%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C295H352Cli2N8O72Si3 2832.4861; found 2832.4761.

[0553] Starting from decasaccharide 40

[0554] Starting from pentadecasaccharide 48

[0555]

[0556] 4-O-Benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4- di-f>-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl- (1— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 —>2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O-benzyl- 3-O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl (7V-phenyl)trifluoroacetimidate (74). The title compound was synthesized from pentadecasaccharide 48 (299 mg, 0.053 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2 + TEA) gave compound 74 (255 mg, 85%, over 2 steps) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C293H353Cli2F3N6O72Si32882.9842; found

[0557] 2882.9759.

[0558] 2-Azidoethyl 4-O-benzyl-3-O-ter?-butyldimethylsilyl-2-O-levulinoyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O- benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6- O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O-benzyl-3- O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-( 1— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 —>2)-4-O-benzyl-3-O-tert-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (70). To a solution of donor 74 (204 mg, 0.036 mmol, 1.0 equiv.) in anhydrous Toluene (1.1 mL), was added activated ground molecular sieves (4A, 408 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -65 °C after which TMSOTf (0.6 pL, 0.004 mmol, 0.1 + 0.1 equiv.) was added. After 10 min, azidopropanol (4 pL, 0.053 mmol, 1.5 equiv., in 1.1 mL of anhydrous Toluene) was added and the mixture was allowed to stir from -60 to -5 °C for 2 h. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (40 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 70 (167 mg, 82%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C295H352Cli2N8O72Si3 2832.4861; found 2832.4761.

[0559] Synthesis of azidopropyl-equipped pentadecasaccharide 79 (3a)

[0560] Starting from pentasaccharide 52

[0561] 3-Azidopropyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1— >3)]-4-O-benzyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (76). The title compound was synthesized from pentasaccharide 52 (100 mg, 0.049 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2) gave compound 76 (84.5 mg, 89%) as a crystalline solid. 'H NMR (400 MHz, CDCh) 5 (ppm): 7.86-7.83 (m, 3H, Ctf-Ar), 7.71 (s, 1H, Ctf-Ar), 7.53-7.46 (m, 4H, Ctf-Ar), 7.39-7. 13 (m, 37H, Ctf-Ar), 7.01 (d, J= 7.5 Hz, 1H, WTCA), 5.56 (s, 1H, H-7D), 5.23 (dd, J= 3.3, 1.8 Hz, H-2C), 5.16 (s, 1H, H-1A), 5.04 (d, JID,2D = 4.8 Hz, H-1D), 5.03 (d, J= 1.5 Hz, H-1B), 4.96 (d, J= 11.1 Hz, 1H, CZ / HPh), 4.92 (d, J = 11.1 Hz, 1H, CZ / HPh), 4.89-4.83 (m, 6H, H-1E, H-1C, CWHPh), 4.74 (d, J= 10.7 Hz, 1H, CZ / HPh), 4.69 (d, J= 11.2 Hz, 1H, CWHPh), 4.66 (d, J = 10.7 Hz, 1H, CZ / HPh), 4.61 (d, J= 10.6 Hz, 1H, CZ / HPh), 4.58-4.48 (m, 6H, H-3D, CWHPh), 4.39 (dd, J= 10.6, 4.8 Hz, 1H, H-6aD), 4.32 (d, J= 11.9 Hz, 1H, CZ / HPh), 4.09 (dd, J= 9.5, 3.1 Hz, 1H, H-3C), 4.05-3.93 (m, 9H, H-3E, H-2B, C#2CA, H-2A, H-3A, H-5C, CZAink, H- 5E), 3.84-3.77 (m, 3H, H-5A, H-3B, H-6bD), 3.75 (t, J = 9.7 Hz, 1H, H-4E), 3.69-3.55 (m, 5H, H-5B, H-4D, CZAink, H-2E, H-5D), 3.52-3.43 (m, 4H, H-4A, H-6aE, H-2D, H-4B), 3.42-3.38 (m, 3H, H-6bE, C^Link), 3.35 (t, J= 9.5 Hz, H-4C), 1.90^1.83 (m, 2H, C^Link), 1.28 (d, J= 6.3 Hz, 3H, H-6B), 1.19 (d, J= 6.2 Hz, 3H, H-6A), 0.72 (d, J= 6.2 Hz, 3H, H-6C). HRMS (ESI-TOF): m / z [M+NH4]+calcd for C104H116CI4N5O24 1958.6759; found 1958.6742.

[0562] 3-Azidopropyl [2,3,4,6-tetra-f?-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (78). Decasaccharide 63 was obtained by an alternative procedure from acceptor 76. Thus, to a solution of the later (242 mg, 0.109 mmol, 1.0 equiv.) in anhydrous Toluene (3.3 mL), were successively added donor 35 (290 mg, 0.136 mmol, 1.25 equiv.) and activated ground molecular sieves (4 A, 106 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -45 °C. After 5 min, TMSOTf (5.0 pL, 0.030 mmol, 0.25 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -40 °C to rt. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (40 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 63 (317 mg, 75%), as a crystalline solid. The title compound was synthesized from decasaccharide 63 (302 mg, 0.078 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (Tol / EtOAc 95:5 to 85:15) gave compound 78 (250 mg, 85%) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C205H225CI8N7O47 1908.1464; found 1908.1403.

[0563] 3-Azidopropyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-2-O- levulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-t?-benzyl-«-L-rhamnopyranosyl-(l— >3)-2- O-chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene- 2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l—>3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranosyl-(l— >2)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1— >3)]-4-O-benzyl-«- L-rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (79). To a solution of acceptor 78 (105 mg, 0.028 mmol, 1.0 equiv.) in anhydrous Toluene (1.4 mL), were successively added donor 35 (118 mg, 0.055 mmol, 2.0 equiv.) and activated 4A MS (39 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -50 °C. After 5 min, TfOH (or TMSOTf) (1.3 pL, 0.014 mmol, 0.5 equiv.) was added and the reaction mixture was stirred under Ar from -50 °C to rt until TLC shows complete conversion of the starting material. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 79 (114 mg, 71%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C311H336CI12N8O72 2878.4583; found 2878.4529.

[0564] Starting from decasaccharide 42

[0565] Starting from pentadecasaccharide 49 (3a)

[0566] [2,3,4,6-Tetra-O-benzyl-a-D-glucopyranosyl-( 1— >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1 -^2)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l—>3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranosyl-(l— >2)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-«- L-rhamnopyranosyl-( 1— >2)-3,4-di-t?-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl (7V-phenyl)trifluoroacetimidate (77). The title compound was synthesized from pentadecasaccharide 49 (126 mg, 0.022 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2 + TEA) gave compound 77 (98 mg, 78%, over 2 steps) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C316H335CI12F3N6O72 2921.9485; found 2921.9380.

[0567] 3-Azidopropyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-2-O- levulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-t?-benzyl-«-L-rhamnopyranosyl-(l— >3)-2- O-chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene- 2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1 ^2)-|2.3.4.6-tetra-6Mienzyl-( / -l)- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl rhamnopyranosyl-(l—>3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranosyl-(l— >2)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1— >3)]-4-O-benzyl-«- L-rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (79). To a solution of donor 77 (97 mg, 0.017 mmol, 1.0 equiv.) in anhydrous Toluene (0.5 mL), was added activated 4A MS (194 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -69 °C, after which TMSOTf (1.0 pL, 0.003 mmol, 0.1 equiv.) was added. After 10 min, azidopropanol (2.0 pL, 0.025 mmol, 1.5 equiv., in 0.2 mL of anhydrous Toluene) was added and the mixture was stirred from -65 to -0 °C for 2 h. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (40 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 79 (66 mg, 68%), as a crystalline solid.

[0568] Example 16: Synthesis of heterooligosaccharides (or chimeric oligosaccharides)

[0569] Chloroacetyl conversion into acetyl of pentasaccharides lb and 3a

[0570]

[0571] Allyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl- ( 1 — >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1 —>3)-2-O-acetyl-4-O-(2-naphtylmethyl)- «-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (83). The compound 28 (650 mg, 0.307 mmol, 1.0 equiv.) was dissolved in a mixture of water / Py (1 :1, 18.4 mL). The suspension was stirred at 55 °C overnight. After evaporation and coevaporation with toluene under reduced pressure, the obtained crude was dissolved in a mixture of Ac2O / Py (1 : 1, 18 mL). DMAP (3.3 mg, 0.03 mmol, 0.1 equiv.) was added and the suspension was allowed to run overnight at rt under Ar. Solvents were eliminated under reduced pressure and co-evaporated with toluene (3 x 2 mL). The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 8:2) to give compound 83 (575 mg, 92%, over 2 steps), as a crystalline solid. HRMS (ESI- TOF): m / z [M+NH4]+cal cd for CiisHnsCh^CheSi 2095.8367 found 2095.8405.

[0572] Allyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?- benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O-(2-naphtylmethyl rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (83a). The title compound was synthesized from pentasaccharide 83 (574 mg, 0.276 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2) gave compound 83a (504 mg, 92%) as a crystalline solid.JH NMR (500 MHz, CDC13) 5 (ppm): 7.83-7.79 (m, 4H, WTCA, Ctf-Ar), 7.72 (s, 1H, Ctf-Ar), 7.49-7.45 (m, 2H, Ctf-Ar), 7.39 (dd, J = 8.3, 1.6 Hz, 1H, Ctf-Ar), 7.36-7.29 (m, 13H, Ctf-Ar), 7.27— 7. 19 (m, 23H, Ctf-Ar), 7.16-7.08 (m, 6H, Ctf-Ar), 5.95-5.87 (m, 1H, H-2AII), 5.31 (ddd, J= 17.2, 4.0, I.8 Hz, 1H, H-3aAn), 5.21^5.18 (m, 2H, H-2C, H-3bAn), 5.06 (d, J= 1.5 Hz, 1H, H-1B), 5.04 (d, J= 1.3 Hz, 1H, H-1A), 5.02 (d, J= 1.6 Hz, 1H, H-1C), 4.92 (d, J= 11.4 Hz, 1H, C / ZHPh), 4.87 (d, J= 11.0 Hz, 1H, C / ZHPh), 4.85 (d, J= 10.7 Hz, 1H, C / ZHPh), 4.81 -4.76 (m, 6H, H- 1E, H-1D, CT / HPh), 4.65-4.57 (m, 5H, C / ZHPh), 4.55-4.48 (m, 3H, C / ZHPh), 4.43 (d, J =

[0573] I I.1 Hz, 1H, C / ZHPh), 4.41 (d, J= 10.8 Hz, 1H, C / ZHPh), 4.26 (ddt, J= 12.9, 5.0, 1.9 Hz, 1H, H-laAn), 4.24-4.20 (m, 2H, H-2D, C / ZHPh), 4.14^4.11 (m, 1H, H-5D), 4.07-3.97 (m, 7H, H- 3C, H-lbAn, H-3A, H-6aD, H-2A, H-4D, H-3D), 3.94 (dd, J= 3.5, 1.7 Hz, 1H, H-2B), 3.90 (t, J= 9.1 Hz, 1H, H-3E), 3.82 (dd, J= 9.3, 2.5 Hz, 1H, H-3B), 3.79-3.66 (m, 6H, H-5A, H-5B, H-5E, H-5C, H-6bD, H-4E), 3.62 (dd, J= 11.0, 2.5 Hz, 1H, H-6aE), 3.53 (dd, J= 9.8, 2.5 Hz, 1H, H-2E), 3.49 (tJ= 9.2 Hz, 1H, H-4C), 3.43 (tJ= 9.1 Hz, 1H, H-4B), 3.34 (dd, J= 10.5, 1.7 Hz 1H, H-6bE), 3.32 (t, J= 9.1 Hz, 1H, H-4A), 2.15 (s, 3H, CH^, 1.25 (d, J= 6.3 Hz, 3H, H- 6B), 1.17 (d, J= 6.4 Hz, 3H, H-6C), 1.02 (d, J= 6.3 Hz, 3H, H-6A), 0.95 (s, 9H, C(C / f3)3), 0.12 (s, 3H, C#3Si), 0.10 (s, 3H, C#3Si). HRMS (ESI-TOF): m / z [M+NH4]+calcd for CnoHi32Cl3N2026Si 1997.7999 found 1997.8053.

[0574] Allyl 3,4-di-f?-benzyl-«-L-rhamnopyranosyl-(1^2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-

[0575] ( 1 — >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (84). To a solution of compound 83 (1.0 g, 0.481 mmol, 1.0 equiv.) in a mixture of Py / AcOH (1 :1, 14 mL) stirred at 0 °C under Ar, was added hydrazine monohydrate (50-60%, 51 pL, 0.577 mmol, 1.2 equiv.). The mixture was stirred for 2 h while being gradually warmed to rt. Following addition of EtOAc (100 mL), the organic phase was washed with an aqueous solution of CuSO4(3 x 20 mL). The combined organic phases were washed with water (40 mL), brine (40 mL) and dried over Na2SO4. The filtrate was concentrated under reduced pressure to give crude alcohol 83a. The crude residue was dissolved in anhydrous THF (31 mL) and stirred at rt under Ar. TEA.3HF (4.7 mL, 28.836 mmol, 60 equiv.). was added and the reaction mixture was stirred at 30 °C overnight. The suspension was cooled to rt, diluted with EtOAc (100 mL). The organic phase was washed with saturated aqueous NaHCO3(30 mL), water (30 mL) and brine (30 mL), dried over Na2SO4and concentrated to dryness. The obtained residue was solubilized in anhydrous ACN (18 mL) and the mixture was stirred at rt under Ar. Iron-dibm complex (93.0 mg, 0.179 mmol, 0.4 equiv.), TBAB (43 mg, 0.134 mmol, 0.3 equiv.), Ag2O (104 mg, 0.448 mmol, 1.0 equiv.) and BnBr (107 pL, 0.896 mmol, 2.0 equiv.) were added to the suspension and the reaction was allowed to stir at 40 °C for 45 min. The resulting mixture was cooled down to rt and diluted with DCM, filtered through Celite and concentrated to dryness. The crude was finally purified by flash chromatography (Tol / EtOAc 95:5 to 85: 15) to give compound 84 (791 mg, 84% over 3 steps), as a yellow solid 'H NMR (400 MHz, CDC13) 5 (ppm): 7.85-7.81 (m, 4H, C / 7-Ar), 7.76 (s, 1H, C77-Ar), 7.52-7.47 (m, 2H, C / 7-Ar), 7.42 (dd, J= 8.4, 1.5 Hz, 1H, C / 7-Ar), 7.39—7.21 (m, 35H, C77-Ar), 7.19^7.11 (m, 5H, C / 7-Ar), 5.99-5.89 (m, 1H, H-2AII), 5.34 (ddd, J= 17.3, 3.8,

[0576] 1.6 Hz, 1H, H-3aAn), 5.24-5.20 (m, 2H, H-2C, H-3bAn), 5.09 (d, JIB,2B = 1.6 Hz, 1H, H-1B), 5.05 (br s, 2H, H-1A, H-1C), 4.96 (d, J = 11.6 Hz, 1H, CZ / HPh), 4.91 -4.78 (m, 8H, H-1E, H- 1D, CT / HPh), 4.69-4.44 (m, 12H, CZ / HPh), 4.29 (ddt, J = 12.9, 5.0, 1.5 Hz, 1H, H-la^i), 4.27-4.23 (m, 2H, H-2D, CZ / HPh), 4.18^4.14 (m, 1H, H-5D), 4.11^4.01 (m, 6H, H-2A, H- 3C, H-lbAn, H-6aD, H-2B, H-3D), 3.93 (t, J= 9.3 Hz, 1H, H-3E), 3.85 (dd, J= 8.8, 2.8 Hz, 1H, H-3B), 3.82-3.68 (m, 7H, H-3A, H-5A, H-5B, H-5E, H-5C, H-6bD, H-4E), 3.66 (dd, J= 10.7,

[0577] 2.7 Hz, 1H, H-6aE), 3.56 (dd, J= 10.5, 3.7 Hz, 1H, H-2E), 3.53 (t, J= 9.3 Hz, 1H, H-4C), 3.44 (t, J = 9.2 Hz, 1H, H-4B) , 3.43 (t, J = 9.3 Hz, 1H, H-4A), 3.38 (dd, J= 10.8, 1.6 Hz, 1H, H- 6bE), 2.39 (d, J= 1.7 Hz, 1H, OH), 2.18 (s, 3H, CfoH), 1.31 (d, J= 6.2 Hz, 3H, H-6B*), 1.21 (d, J= 6.1 Hz, 3H, H-6C), 1.08 (d, J= 6.2 Hz, 3H, H-6A*).

[0578] Allyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (85). The compound 32 (6.39 g, 3.197 mmol, 1.0 equiv.) was dissolved in a mixture of water / Py (1 :1, 182 mL). The suspension was stirred at 55 °C overnight. After evaporation and coevaporation three times with toluene under reduced pressure, the obtained crude was dissolved in a mixture of Ac2O / Py (1 : 1, 416 mL). DMAP (343 mg, 3.19 mmol, 1.0 equiv.) was added and the suspension was allowed to run overnight at rt under Ar. Following addition of EtOAc (200 mL), the organic phase was washed with an aqueous solution of CuSCh (6 x 50 mL). Then, the combined organic phases were washed with water (200 mL), brine (200 mL), dried over Na2SO4 and concentrated under reduced pressure. The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 85: 15) to give compound 85a (5.73 g, 91%, over 2 steps), as a crystalline solid. HRMS (ESI-TOF): m / z [M+NH4] calcd for C109H122CI3N2O26 1979.7346 found 1979.7346. The title compound was synthesized from pentasaccharide 85a (550 mg, 0.280 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2) gave compound 85 (477 mg, 91%) as a crystalline solid. HRMS (ESI-TOF): m / z [M+NH4]+calcd for C104H116CI3N2O24 1881.6978 found 1881.6970.

[0579] [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1 — >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl (TV-phenyl)trifluoroacetimidate (86). The title compound was synthesized from pentasaccharide 85a (1.13 mg, 0.576 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2 + TEA) gave compound 86 (1.02 g, 87%, over 2 steps) as a crystalline solid. HRMS (ESI-TOF): m / z [M+NH4]+calcd for C114H122CI3F3N3O26 2110.7329 found 2110.7357.

[0580] Heterocoupling of donor 2a / acceptor lb

[0581] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-«-L-rhamnopyranosyl-( 1— >2)-3,4-di-f?- benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O-(2-naphtylmethyl rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (83a). The title compound was synthesized from pentasaccharide 83 (574 mg, 0.276 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2) gave compound 83a (504 mg, 92%) as a crystalline solid. HRMS (ESI-TOF): m / z [M+NH4]+calcd for CiioHi32C13N2026Si 1997.7999 found 1997.8053. Allyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl- (1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O- benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O-benzyl-3-O- terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl- ( 1 — >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (87). To a solution of acceptor 83a (250 mg, 0.124 mmol, 1.0 equiv.) in anhydrous Toluene (6.2 mL), was added activated 4A MS (170 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -40 °C and stirred for another 5 min. After that time, TBSOTf (6.5 pL, 0.037 mmol, 0.3 equiv.) was added at this temperature and donor 34 (339 mg, 0.161 mmol, 1.3 equiv.) was slowly added within 20 min from -35 to -30 °C. Then, the reaction mixture was allowed to stir under Ar from -30 to 0 °C for 1 h and EtsN was added. The suspension was filtered over Celite, rinsed with DCM (30 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (cHex / EtOAc 95:5 to 75:25) to give compound 87 (435 mg, 90%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C2iiH253C17N4O49Si2 1963.7288 found 1963.7457.

[0582] 4-O-Benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4- di-f>-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl- (1— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 — >2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O-acetyl-4- f>-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl (7V-phenyl)trifluoroacetimidate (87a). The title compound was synthesized from decasaccharide 87 (346 mg, 0.089 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (TolZEtOAc 95:5 to 8:2 + TEA) gave compound 87a (319 mg, 90%, over 2 steps) as a crystalline solid. HRMS(ESI-TOF): m / z [M+2NH4]2+calcd for C2i6H253C17F3N5O49Si2 2029.7395 found 2029.7364.

[0583] 3-Azidopropyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f>- benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6- O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O-benzyl-3- O-tert-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-t?-benzyl-«-L- rhamnopyranosyl-( l—>3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl- ( 1 — >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (88). To a solution of PTFA donor 87a (219 mg, 0.054 mmol, 1.0 equiv.) in anhydrous Toluene (2.7 mL) was added activated ground molecular sieves (4A, 438 mg). The mixture was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -60 °C. After 5 min, TMSOTf (2.0 pL, 0.011 mmol, 0.2 equiv.) was added. After 5 min, azidopropanol (8.0 pL, 0.082 mmol, 1.5 equiv.) was added to the suspension and the reaction mixture was allowed to stir under Ar for 2 h from -56 to -15 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (30 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (TolZEtOAc 95:5 to 85: 15) to give compound 88 (186 mg, 87%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C2iiH254C17N7O49Si21985.2473 found 1985.2535.

[0584] Heterocoupling of donor 3a / acceptor lb

[0585] Allyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1 — >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-f?-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1 — >2)-4-O-benzyl-3-O-terf- butyldimethylsilyl-«-L-rhamnopyranosyl-( l—>2)-3,4-di-f?-benzyl-«-L-rhamnopyranosyl- (1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2, 3,4,6- tetra-O-benzyl-a-D-glucopyranosyl-( 1— >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?- D-glucopyranoside (89). To a solution of acceptor 36 (186 mg, 0.092 mmol, 1.0 equiv.) in anhydrous Toluene (3.7 mL), were successively added donor 35 (236 mg, 0.111 mmol, 1.2 equiv.) and activated ground molecular sieves (4A, 118 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -40 °C. After 5 min, TMSOTf (5.0 pL, 0.028 mmol, 0.5 equiv.) was added and the reaction mixture was allowed to stir under Ar from -40 to 15 °C for 1 h. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (30 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 89 (321 mg, 88%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C2i6H246Cl8N4O49Si 1993.7074; found 1993.7131.

[0586] [2,3,4,6-Tetra-f>-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1 — >2)-4-O-benzyl-3-O-terf- butyldimethylsilyl-«-L-rhamnopyranosyl-( l—>2)-3,4-di-f>-benzyl-«-L-rhamnopyranosyl- (1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2, 3,4,6- tetra-O-benzyl-a-D-glucopyranosyl-( 1— >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?- D-glucopyranosyl (A-phenyl)trifluoroacetimidate (89a). The title compound was synthesized from decasaccharide 89 (321 mg, 0.081 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (TolZEtOAc 95:5 to 8:2 + TEA) gave compound 89a (234 mg, 72%, over 2 steps) as a crystalline solid. HRMS (ESI- TOF): m / z [M+2NH4]2+calcd for C22iH246Cl8F3N5O49Si 2059.7081; 2059.7081.

[0587] 3-Azidopropyl [2,3,4,6-tetra-f>-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-2-O- levulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L-rhamnopyranosyl-(l— >3)-2- O-chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene- 2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O-terf- butyldimethylsilyl-«-L-rhamnopyranosyl-( l—>2)-3,4-di-f>-benzyl-«-L-rhamnopyranosyl- (1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2, 3,4,6- tetra-O-benzyl-a-D-glucopyranosyl-( 1— >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?- D-glucopyranoside (90). To a solution of PTFA donor 89a (232 mg, 0.059 mmol, 1.0 equiv.) in anhydrous Toluene (3.0 mL) was added activated ground molecular sieves (4A, 464 mg). The mixture was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -40 °C. After 5 min, TMSOTf (3.2 pL, 0.018 mmol, 0.3 equiv.) was added. After 5 min, azidopropanol (10 pL, 0.107 mmol, 1.8 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -40 to 15 °C. EtiN was added. The suspension was filtered over Celite, rinsed with DCM (30 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (Tol / EtOAc 95:5 to 85: 15) to give compound 90 (149 mg, 63%), as a crystalline solid. HRMS (ESLTOF): m / z [M+2NH4]2+calcd for C2i6H247Cl8N7O49Si 2015.7175; found 2015.7112.

[0588] Heterocoupling of donor 2a / acceptor 3a

[0589] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-O-levulinoyl-«-L-rhamnopyranosyl- (1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l—>4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l—>3)-4,6-O- benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-[2,3,4,6-tetra-0- benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-( 1— >2)-3,4-di-O- benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (91). To a solution of acceptor 85 (30 mg, 0.016 mmol, 1.0 equiv.) in anhydrous Toluene (1.0 mL), were successively added donor 34 (37 mg, 0.018 mmol, 1.1 equiv.) and activated 4A MS (20 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -40 °C. After 5 min, TMSOTf (0.7 pL, 0.004 mmol, 0.25 equiv.) was added and the reaction mixture was allowed to stir under Ar from -40 to -10 °C for Ih. EttN was added. The suspension was filtered over Celite, rinsed with DCM (10 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 85: 15) to give compound 91 (47 mg, 78%), as a crystalline solid. 'H NMR (500 MHz, CDCh) 5 (ppm): 7.86-7.83 (m, 3H, C / f-Ar), 7.70 (br s, 1H, C / f-Ar), 7.55—7.41 (m, 10H, C / f-Ar), 7.38-7.30 (m, 38H, C77-Ar), 7.27-7.05 (m, 45H, WTCA, C / f-Ar), 6.99 (br s, 1H, WTCA’), 5.91 —5.83 (m, 1H, H-2AII), 5.54 (s, 1H, H-7D’), 5.32-5.26 (m, 2H, H-2A’, H-3aAn), 5.24 (s, 1H, H-7D), 5.21 (ddd, J= 10.5, 3.2, 1.1 Hz, 1H, H-3aAn), 5.17^5.15 (m, 2H, H-1E, H-2C), 5.11 (d, JID,2D = 8.3 Hz, 1H, H-1D), 5.07-4.97 (m, 7H, H-2C’, H-1B’, H-1A, H-1A’, H-1B, C / ZHPh), 4.92-4.79 (m, 12H, H-1E’, H-1C, C / ZHPh), 4.72-4.70 (m, 2H, H-1C’, CWHPh), 4.65-4.46 (m, 20H, H-1D’, H-3D, C / ZHPh), 4.39-4.30 (m, 6H, H-6aD, H-laAn, CWHPh), 4.19 (dd, J = 8.2, 2.6 Hz, 1H, H-3A’), 4.12-3.94 (m, 16H, H-lbAn, H-3E, H-3C’, H-3C, H-3D’, C#2CA, H- 2D’, H-3A, H-2B, H-2B’, H-2A, H-5C, H-5A, H-5E, C / ZHPh), 3.90-3.55 (m, 18H, H-3E’, H- 4E, H-4E’, H-4D’, H-4D, H-3B, H-3B’, H-2E, H-5A’, H-6bD, H-6aD’, H-6bD’, H-6aE, H- 5C’, H-5B, H-5B’, H-5D’, H-5D), 3.48-3.34 (m, 8H, H-4A, H-4B, H-4B’, H-4C’, H-2E’, H- 6bE, H-6aE’, H-2D), 3.31 (t, J= 9.6 Hz, 1 H, H-4C), 3.26 (t, J= 9.3 Hz, 1 H, H-4A‘), 3.07 (br s, 1H, H-6bE’), 2.87 (br s, 1H, H-5E’), 2.65-2.48 (m, 4H, 2 x CH2L^ 2.10 (s, 3H, C#3Lev), 2.05 (s, 3H, C#3Ac), 1.24 (d, J= 6.1 Hz, 6H, H-6B, H-6B’), 1.22 (d, J= 6.0 Hz, 3H, H-6A’), 1.20 (d, J= 6.1 Hz, 3H, H-6C), 0.91 (s, 9H, C(C#3)3), 0.86 (d, J= 5.7 Hz, 3H, H-6A), 0.72 (d, J= 6.1 Hz, 3H, H-6C’), 0.155 (s, 3H, C#3Si), 0.10 (s, 3H, C#3Si).

[0590] 4-O-Benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4- di-f>-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl- (1— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(1^2)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-

[0591] ( 1 — >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl (N- phenyl)trifluoroacetimidate (91a). The title compound was synthesized from decasaccharide 91 (45 mg, 0.012 mmol, 1.0 equiv.) according to the general procedure for PTFA activation by means of the intermediate hemiacetal. Purification by flash chromatography (TolZEtOAc 95:5 to 85: 15 + TEA) gave compound 91a (29 mg, 64%, over 2 steps) as a crystalline solid. HRMS (ESI-TOF) of hemiacetal: m / z [M+2NH4]2+calcd for C202H233C17N4O49Si 1885.6721 found 1885.6767.

[0592] 3-Azidopropyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f>- benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6- f>-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-[2,3,4,6-tetra- f>-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-( 1— >2)-3,4-di-f>- benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (92). To a solution of PTFA donor 91a (29 mg, 0.007 mmol, 1.0 equiv.) in anhydrous Toluene (0.4 mL) was added 4A MS (58 mg). The mixture was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -40 °C. After 5 min, TMSOTf (0.3 pL, 0.001 mmol, 0.2 equiv.) was added. After 5 min, azidopropanol (1.0 pL, 0.011 mmol, 1.5 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -40 to 10 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (10 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (Tol / EtOAc 95:5 to 9: 1) to give compound 92 (21 mg, 75%), as a crystalline solid. HRMS (ESL TOF): m / z [M+2NH4]2+calcd for C205H238C17N7O49Si 1927.1962; found 1927.1999.

[0593] Heterocoupling of donor 3a / acceptor 2a

[0594] Allyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1 — >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 —>2)-4-O-benzyl-3-O-tert-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (93). To a solution of acceptor 37 (30 mg, 0.016 mmol, 1.0 equiv.) in anhydrous Toluene (1.0 mL), were successively added donor 86 (37 mg, 0.018 mmol, 1.1 equiv.) and activated 4A MS (18 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -40 °C. After 5 min, TMSOTf (0.7 pL, 0.004 mmol, 0.25 equiv.) was added and the reaction mixture was allowed to stir under Ar from -40 to -10 °C for Ih. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (10 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (Tol / EtOAc 95:5 to 85: 15) to give compound 93 (51 mg, 84%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C205H237C17N4O49Si 1906.1894 found 1906.1871.

[0595] [2,3,4,6-Tetra-O-benzyl-a-D-glucopyranosyl-( 1— >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 —>2)-4-O-benzyl-3-O-terCbutyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- f>-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl (N- phenyl)trifluoroacetimidate (93a). The title compound was synthesized from decasaccharide 93 (48 mg, 0.013 mmol, 1.0 equiv.) according to the general procedure for PTFA activation by means of the hemiacetal intermediate. Purification by flash chromatography (Tol / EtOAc 95:5 to 9: 1 + TEA) gave compound 93a (38 mg, 77%, over 2 steps) as a crystalline solid. HRMS (ESI-TOF) of hemiacetal: m / z [M+2NH4]2+calcd for C202H233C17N4O49Si 1886.1737 found 1886.1716.

[0596] 3-Azidopropyl [2,3,4,6-tetra-f?-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-2-O- levulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L-rhamnopyranosyl-(l— >3)-2- f>-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O-terf- butyldimethylsilyl-«-L-rhamnopyranosyl-( l—>2)-3,4-di-f>-benzyl-«-L-rhamnopyranosyl- (1— >3)-[2,3,4,6-tetra-f?-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (94). To a solution of PTFA donor 93a (38 mg, 0.010 mmol, 1.0 equiv.) in anhydrous Toluene (0.6 mL) was added activated ground molecular sieves (4A, 77 mg). The mixture was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -40 °C. After 5 min, TMSOTf (0.8 pL, 0.004 mmol, 0.4 equiv.) was added. After 5 min, azidopropanol (1.0 pL, 0.015 mmol, 1.5 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -40 °C to rt. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (10 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 94 (29 mg, 80%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C205H238C17N7O49Si 1928.1974 found 1928.1931.

[0597] Heterocoupling of donor 2a2a / acceptor lb

[0598] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-O-levulinoyl-«-L-rhamnopyranosyl-

[0599] ( 1 — >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1 -^3)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O- benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O-benzyl-3-O- terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 — >2)-4-O-benzyl-3-O-tert-butyldimethylsilyl-«- L-rhamnopyranosyl-( 1— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4- O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-(l— >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside

[0600] (95). To a solution of acceptor 83a (127 mg, 0.064 mmol, 1.0 equiv.) in anhydrous Toluene (6.2 mL), were successively added donor 61 (326 mg, 0.083 mmol, 1.3 equiv.) and 4AMS (651 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -42 °C. After 5 min, TfOH (2.3 pL, 0.026 mmol, 0.4 equiv.) was added and the reaction mixture was allowed to stir under Ar from -40 to 0 °C for Ih. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (30 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 8:2) to give compound 95 (345 mg, 94%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C307H364ClnN5O72Si3 2871.5438; found 2871.5429.

[0601] 4-O-Benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4- di-f>-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl- (1— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- f>-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl- 3-O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl- ( 1 — >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl (A-phenyl)trifluoroacetimidate (95a). The title compound was synthesized from pentadecasaccharide 95 (302 mg, 0.053 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2 + TEA) gave compound 95a (234 mg, 75%, over 2 steps) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C3i2H364ClnF3N6O72Si3 2937.5434; found 2937.5339.

[0602] 3-Azidopropyl 4-6M)enzyl-3-O- / c / 7-butyldimethylsilyl-2-O-levulinoyl-<z-l - rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f>- benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6- f>-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3- O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-( 1^3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O-acetyl-4- f>-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (96). To a solution of PTFA donor 95a (233 mg, 0.040 mmol, 1.0 equiv.) in anhydrous Toluene (1.8 mL) was added 4A MS (233 mg). The mixture was stirred at rt for 15 min under Ar and cooled to -55 °C. After 5 min, TMSOTf (2.0 pL, 0.012 mmol, 0.3 equiv.) was added. After 5 min, azidopropanol (6.0 pL, 0.060 mmol, 1.5 equiv.) was added to the suspension and the reaction mixture was allowed to stir under Ar for 1 h from -50 to 10 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (30 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 96 (189 mg, 82%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for CsovIfcesCliiNsC^Sis 2893.0523; found 2893.0558. Heterocoupling of donor 3a3a / acceptor lb

[0603] Allyl [2,3,4,6-tetra-f>-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 -^2)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-

[0604] ( 1 — >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (97). To a solution of acceptor 85 (450 mg, 0.241 mmol, 1.0 equiv.) in anhydrous Toluene (9.6 mL), were successively added donor 86 (657 mg, 0.313 mmol, 1.3 equiv.) and 4A MS (900 mg). The suspension was stirred at rt for 15 min under Arand cooled to -50 °C. After 5 min, TfOH (9.6 pL, 0.108 mmol, 0.45 equiv.) was added and the reaction mixture was allowed to stir under Ar for 5 h from -50 to 10 °C. Et3N was added. The suspension was filtered over Celite, rinsed with DCM (40 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 97 (795 mg, 87%), as a crystalline solid. 'HNMR (400 MHz, CDC13) 8 ppm: 7.87-7.87 (m, 6H, Ctf-Ar), 7.71 (br s, 2H, Ctf-Ar), 7.57-7.44 (m, 7H, Ctf-Ar), 7.40-7.27 (m, 44H, Ctf-Ar), 7.25-7.05 (m, 36H, WTCA, Ctf-Ar), 7.03-6.98 (m, 2H, Ctf-Ar), 6.91 (d, J= 9.5 Hz, 1H, W’TCA), 5.92-5.82 (m, 1H, H-2AII), 5.55 (s, 1H, H-7D’), 5.52 (t, J= 3.4 Hz, 1H, H-2A’), 5.29 (ddd, J= 17.2, 3.4, 1.3 Hz, 1H, H-3aAn), 5.22-5.20 (m, 3H, H-3bAn, H-7D, H-1E’), 5.16 (dd, J= 3.5, 1.9 Hz, 1H, H-2C), 5.14 (d, JIE,2E = 3.5 Hz, 1H, H-1E), 5.11 (d, JID,2D= 8.3 HZ, 1H, H-1D), 5.08-4.95 (m, 8H, H-2C’, H-1B’, H- 1A, H-1B C / ZHPh), 4.91 —4.75 (m, 12H, H-1A’, H-1C, C / ZHPh), 4.72-4.43 (m, 21H, H-1C’, H-1D’, H-3D’, C / ZHPh), 4.40-4.21 (m, 6H, H-6aD, H-laAn, H-3A’, C / ZHPh), 4.16-3.97 (m, 13H, H-3E, H-lbAii, H-3C’, H-3C, H-3E’, H-3A, H-2A, H-2D’, H-5D’, H-4D’, H-5E, H-5C, H-2B), 3.93 (t, J= 3.4 Hz, 1H, H-2B’), 3.91^3.71 (m, 11H, H-5A’, H-5C’, H-5B’, H-2E’, H- 3B’, H-3B, H-5A, H-6bD, H-6aE, H-4E’, H-5E’), 3.70-3.64 (m, 1H, H-5B), 3.63-3.56 (m, 5H, H-4E, H-2E, H-5D, H-6aE’, H-6bE’), 3.54-3.39 (m, 7H, H-4B’, H-4A’, H-4A, H-4B, H- 2D, H-6aD’, H-6bD’), 3.32 (td, J= 9.1, 3.4 Hz, 2H, H-4C, H-4C’), 3.23 (t, J= 9.4 Hz, 1H, H- 4D), 2.99 (t, J= 10.0 Hz, 1H, H-6bE), 2.88 (t, J= 9.6 Hz, 1H, H-3D), 2.84-2.79 (m, 1H, H- 5E), 2.56-2.34 (m, 4H, 2 x C#2Lev), 2.07 (s, 3H, C#3Ac), 2.05 (s, 3H, C / Av), 2.03 (s, 3H, CZZsLev), 1.35 (d, J= 6.0 Hz, 3H, H-6B), 1.26 (d, J= 6.3 Hz, 3H, H-6B’), 1.24 (d, J= 6.2 Hz, 3H, H-6A), 1.20 (d, J= 6.1 Hz, 3H, H-6A’), 0.74 (d, J= 6.1 Hz, 3H, H-6C), 0.67 (d, J= 6.0 Hz, 3H, H-6C’).

[0605] [2,3,4,6-Tetra-O-benzyl-a-D-glucopyranosyl-( 1— >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-( l->3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(1^2)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-

[0606] ( 1 — >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl (N- phenyl)trifluoroacetimidate (98). The title compound was synthesized from decasaccharide 97 (243 mg, 0.064 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (TolZEtOAc 95:5 to 8:2 + TEA) gave compound 98 (220 mg, 88%, over 2 steps) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C215H232CI6F3N5O49 1967.1944 found 1967.1868.

[0607] 3-Azidopropyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-2-O- levulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L-rhamnopyranosyl-(l— >3)-2- O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-( 1 — >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1 ^2)-|2.3.4.6-tetra-6Mienzyl-( / -l)- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl- (1— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O- benzyl-3-O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-( l—>3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl- ( 1 — >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (99). To a solution of acceptor 55 (42 mg, 0.021 mmol, 1.0 equiv.) in anhydrous Toluene (1.0 mL), were successively added donor 98 (97 mg, 0.025 mmol, 1.2 equiv.) and activated ground molecular sieves (4A, 900 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -44 °C. After 5 min, TMSOTf (1.1 pL, 0.006 mmol, 0.3 equiv.) was added at this temperature and the reaction mixture was allowed to stir under Ar for 1 h from -40 to -10 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (10 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 99 (107 mg, 89%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C3i7H355C19N8O72Si 2885.0677; found 2885.0803.

[0608] Heterocoupling of donor 2a2a / acceptor 3a

[0609]

[0610] 3-Azidopropyl 4-O-benzyl-3-O-ter?-butyldimethylsilyl-2-O-levulinoyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O- benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6- O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O-benzyl-3-

[0611] O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-(l—>3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl- ( 1 — >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (100). To a solution of acceptor 57 (65 mg, 0.034 mmol, 1.0 equiv.) in anhydrous Toluene (2.2 mL), were successively added donor 61 (167 mg, 0.043 mmol, 1.25 equiv.) and 4A MS (83 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -42 °C. After 5 min, TMSOTf (1.5 pL, 0.009 mmol, 0.25 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -40 to -5 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (10 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (TolZEtOAc 95:5 to 8:2) to give compound 100 (118 mg, 93%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C3oiH349CliiN8072Si2 2835.0012; found 2835.0039.

[0612] Heterocoupling of donor 3a / acceptor 2a2a

[0613] Allyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1 — >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 —>2)-4-O-benzyl-3-O-tert-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl- 3-O-tert-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-t?-benzyl-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (101). To a solution of acceptor 45 (158 mg, 0.043 mmol, 1.0 equiv.) in anhydrous Toluene (3 mL), were successively added donor 86 (99 mg, 0.047 mmol, 1.1-1.25 equiv.) and 4A MS (49 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -40 °C. After 5 min, TMSOTf (1.9 pL, 0.011 mmol, 0.25 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -40 to 0 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 85:15) to give compound 101 (162 mg, 67%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for CsoiJ^sClnNsC^Si 2812.9929 found 2812.9984.

[0614] [2,3,4,6-Tetra-O-benzyl-a-D-glucopyranosyl-( 1— >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-(1^3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl- 3-O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl ( V-phenyl)trifluoroacetimidate (102). The title compound was synthesized from pentadecasaccharide 101 (160 mg, 0.029 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (Tol / EtOAc 95:5 to 85:15 + TEA) gave compound 102 (119 mg, 72%, over 2 steps) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C306H348C17F3N6O72Si2 2978.9919 found 2879.0051.

[0615] 3-Azidopropyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-2-O- levulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-2- O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O-terf- butyldimethylsilyl-«-L-rhamnopyranosyl-( l—>2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl- (1— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranosyl-(l— >2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl- (1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6-O- benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (103). To a solution of PTFA donor 102 (118 mg, 0.021 mmol, 1.0 equiv.) in anhydrous Toluene (1.2 mL) was added 4A MS (236 mg). The mixture was stirred at rt for 15 min under Ar and cooled to -40 °C. After 5 min, TMSOTf (1.0 pL, 0.005 mmol, 0.25 equiv.) was added. After 5 min, azidopropanol (3.0 pL, 0.035 mmol, 1.7 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -40 to -10 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (TolZEtOAc 95:5 to 8:2) to give compound 103 (88 mg, 76%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C3oiH349CliiN8072Si2 2835.0012 found 2835.0091.

[0616] Heterocoupling of donor 2a2a / acceptor Iblb

[0617] 4-O-Benzyl-3-O-tert-butyldimethylsilyl-2-O-levulinoyl-«-L-rhamnopyranosyl-( 1— >2)-3,4- di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O-(2-naphtylmethyl rhamnopyranosyl-( 1— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido-a / p-D-glucopyranosyl (N- phenyl)trifluoroacetimidate (105). The title compound was synthesized from pentasaccharide 83 (500 mg, 0.240 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (Tol / EtOAc 95:5 to 85: 15 + TEA) gave compound 105 (502 mg, 91%, over 2 steps) as a crystalline solid. TLC: R / 0.7 (Tol / EtOAc 85: 15 + TEA) Allyl 4-O-beiizyl-3-O- / c / 7-biityldiinethylsilyl-2-O-leviiliiioyl-<z-l -rh:ininopyranosyl- ( 1 — >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1 —>3)-2-O-acetyl-4-O-(2-naphtylmethyl)- «-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-( 1— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (106). To a solution of acceptor 84 (100 mg, 0.051 mmol, 1.0 equiv.) in anhydrous Toluene (5.1 mL), were successively added donor 105 (136 mg, 0.061 mmol, 1.2-1.4 equiv.) and 4A MS (542 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -47 °C. After 5 min, TfOH (2.3 pL, 0.026 mmol, 0.5 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -40 to 0 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (30 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 85:15) to give compound 106 (221 mg, quant.), as a crystalline solid. HRMS (ESLTOF): m / z [M+2NH4]2+calcd for C223H256C16N4O49Si 2005.7776; found 2005.7842.

[0618] 4-O-Benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl-( 1— >2)-3,4- di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O-(2-naphtylmethyl rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl (A-phenyl)trifluoroacetimidate (107). The title compound was synthesized from decasaccharide 106 (375 mg, 0.094 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2 + TEA) gave compound 107 (246 mg, 71%, over 2 steps) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C228H256Cl6F3N5O49Si 2072.2783; found 2072.2524. 3-Azidopropyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4- di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O-(2-naphtylmethyl )-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L- rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (108). To a solution of PTFA donor 107 (244 mg, 0.021 mmol, 1.0 equiv.) in anhydrous Toluene (2.4 mL) was added 4A MS (488 mg). The mixture was stirred at rt for 15 min under Ar. Then, the reaction flask was cooled to -65 °C. After 5 min, TMSOTf (3.0 pL, 0.018 mmol, 0.3 equiv.) was added. After 5 min, azidopropanol (9.0 pL, 0.101 mmol, 1.7 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -60 to 10 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (30 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 108a (182 mg, 77%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C223H257C16N7O49Si 2028.2876; found 2028.2788.

[0619] Then, the title compound was synthesized from decasaccharide 108a (182 mg, 0.045 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (TolZEtOAc 95:5 to 8:2) gave compound 108 (104 mg, 59%) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C2i8H25iCl6N7O47Si 1978.7697; found 1978.7643.

[0620] 3-Azidopropyl 4-O-benzyl-3-O- / c / 7-butyldimethylsilyl-2-O-levulinoyl-<z-l - rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f>- benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6- f>-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3- O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-( 1^3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O-acetyl-4- f>-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-(l— >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl- ( 1 — >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1 -^2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl- (1— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O-benzyl-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (109). To a solution of acceptor 108 (104 mg, 0.026 mmol, 1.0 equiv.) in anhydrous Toluene (2.6 mL), were successively added donor 61 (210 mg, 0.053 mmol, 1.4-2.0 equiv.) and 4A MS (436 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -43 °C. After 5 min, TfOH (2.8 pL, 0.032 mmol, 1.2 equiv.) was added and the reaction mixture was allowed to stir under Ar for 5 h from -40 to 10 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (30 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (TolZEtOAc 95:5 to 8:2) to give compound 109 (153 mg, 77%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C^sH^CluNsiCbsSis 3843.3958; found 3843.3818.

[0621] Heterocoupling of donor 2a2a / acceptor 3a3a 3-Azidopropyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1— >3)]-4-O-benzyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-(l—>3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(1^2)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-

[0622] ( 1 — >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (110). The title compound was synthesized from decasaccharide 60 (490 mg, 0.128 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2) gave compound 110 (377 mg, 79%) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C205H227CI6N7O47 1874.1845; found 1874.1803.

[0623] 3-Azidopropyl 4-O-beiizyl-3-O- / c / 7-biityldiniethylsilyl-2-O-leviilinoyl-<z-l - rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f>- benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6- O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O-benzyl-3- O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-( l->3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(1^2)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl- (1— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)- [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1 — >3)]-4-O-benzyl-«-L-rhamnopyranosyl- ( 1 — >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1 — >3)-2-O-acetyl-4-O-(2-naphtylmethyl)- «-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (111). To a solution of acceptor 110 (100 mg, 0.027 mmol, 1.0 equiv.) in anhydrous Toluene (1.7 mL), was added 4A MS (200 mg). The suspension was stirred at rt for 15 min under Ar, cooled to -50 °C and stirred for another 5 min. TMSOTf (1.5 pL, 0.008 mmol, 0.3 + 0.3 equiv.) was added and donor 61 (127 mg, 0.032 mmol, 1.2 + 0.3 equiv.) was added within 60 min from -50 to -35 °C. Then, the reaction mixture was allowed to stir under Ar from -35 to 5 °C for 5 h and EtsN was added. The suspension was filtered over Celite, rinsed with DCM (30 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 75:25) to give compound 111 (181 mg, 90%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C402H455Cli4N9O95Si2 3739.8134; found 3739.8517.

[0624] Heterocoupling of donor 3a3a / acceptor 2a2a 3-Azidopropyl 4-O-benzyl-3-O-ferf-butyldimethylsilyl-«-L-rhamnopyranosyl-( l->2)-3,4- di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl- (1— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 —>2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-

[0625] 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (113).

[0626] Firstly, to a solution of PTFA donor 74 (476 mg, 0.121 mmol, 1.0 equiv.) in anhydrous Toluene (7.3 mL) was added 4AMS (953 mg). The mixture was stirred at rt for 15 min under Ar and cooled to -55 °C. After 5 min, TMSOTf (7.0 pL, 0.036 mmol, 0.3 equiv.) was added. After 5 min azidopropanol (17.0 pL, 0.182 mmol, 1.5 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -55 to -30 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (30 mL) and concentrated under reduced pressure. Then, the title compound was synthesized from the crude linker-equipped decasaccharide (461 mg, 0.121 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (TolZEtOAc 95:5 to 8:2) gave compound 113 (312 mg, 69% over 2 steps) as a crystalline solid. HRMS (ESI-TOF): m / z [M+NH4]+calcd for Ci95H223Cl8N6O47Si2 3746.3068; found 3746.3288.

[0627] 3-Azidopropyl [2,3,4,6-tetra-f>-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-2-O- levulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L-rhamnopyranosyl-(l— >3)-2- f>-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(1^2)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl- (1— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O- benzyl-3-O-tert-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O- chloroacetyl-«-L-rhamnopyranosyl-( 1^3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- f>-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (114). To a solution of acceptor 113 (80 mg, 0.021 mmol, 1.0 equiv.) in anhydrous Toluene (1.4 mL), were successively added donor 98 (100 mg, 0.026 mmol, 1.2 equiv.) and 4A MS (201 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -42 °C. After 5 min, TfOH (1.2 pL, 0.006 mmol, 0.3 equiv.) was added and the reaction mixture was allowed to stir under Ar for 2 h from -40 to 5 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 114 (121 mg, 77%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+NH4]+calcd for C402H455Cli4N9O95Si23740.3135; found 3740.3468.

[0628] Heterocoupling of donor 3a / acceptor 2alb

[0629] Allyl 4-O-benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl- (1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6-O- benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-3,4-di-O-«-L- rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (H5). To a solution of acceptor 84 (140 mg, 0.071 mmol, 1.0 equiv.) in anhydrous Toluene (3.6 mL), were successively added donor 34 (180 mg, 0.086 mmol, 1.2 equiv.) and 4AMS (361 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -40 °C. After 5 min, TfOH (2.5 pL, 0.029 mmol, 0.4 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -40 to 10 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 115 (241 mg, 88%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C2i2H245C17N4O49Si 1951.7190; found 1951.7194. Allyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 —>2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-3,4-di-O- benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O- acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (116). Firstly, the title compound was synthesized from decasaccharide 115 (240 mg, 0.062 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2) gave acceptor 115a (190 mg, 81%) as a crystalline solid. 'H NMR (400 MHz, CDC13) 5 (ppm): 7.69-7.66 (m, 3H, WTCA, Ctf-Ar), 7.60 (br s, 1H, Ctf-Ar), 7.37-7.34 (m, 2H, Ctf-Ar), 7.30-7.16 (m, 30H, Ctf-Ar), 7.15—6.94 (m, 49H, WTCA’, Ctf-Ar), 5.82-5.72 (m, 1H, H-2AII), 5.22 (s, 1H, H-7D’), 5.23 (ddd, J= 17.3, 3.5, 1.7 Hz, 1H, H-3aAn), H-2A’), 5.07-5.04 (m, 3H, H-3bAn, H-2C, H-2C’), 4.97 (br s, 1H, H-1A’), 4.94 (br s, 1H, H-1B), 4.88 (br s, 2H, H-1C, H-1A), 4.97 (br s, 1H, H- 1B’), 4.79—4.61 (m, 16H, H-1E’, H-1C’, H-1D’, H-1E, H-1D, CWHPh), 4.57 (d, J= 11.8 Hz, 1H, CWHPh), 4.50-4.28 (m, 20H, H-3D’, CWHPh), 4. 16-4.06 (m, 3H, H-laAn, H-2D, CWHPh), 4.01 —3.97 (m, 2H, H-3C’, H-5D), 3.95-3.77 (m, 14H, H-lbAn, H-3E, H-3C, H-2A, H-2B, H-3A’, H-4D, C#2CA’, H-2A’, H-2B’, H-6aD, H-3D, H-5A’), 3.75-3.47 (m, 18H, H- 3E’, H-2D’, H-3A, H-3B, H-3B’, H-4E, H-4E’, H-5E, H-6bD, H-5A, H-5C, H-5C’, H-6aD’, H-6bD’, H-6aE’, H-6aE, H-5B, H-5E’), 3.45-3.20 (m, 11H, H-4B, H-4A’, H-4C’, H-4A, H- 4B’, H-2E, H-2E’, H-4D’, H-4C, H-5B’, H-6bE), 3.1 1 -3.09 (m, 2H, H-5D’, H-6bE’), 2.01 (s, 3H, C#3Ac), 1.16 (d, J= 6.1 Hz, 6H, H-6C’*, H-6A’*), 1.04 (d, J= 6.0 Hz, 6H, H-6B*, H-6A*), 0.94 (d, J= 6.2 Hz, 3H, H-6C), 0.82 (s, 9H, C(C / f3)3), 0.69 (d, J= 6.0 Hz, 3H, H-6B’), 0.00 (s, 6H, 2 x C#3Si).

[0630] Secondly, to a solution of the obtained acceptor 115a (190 mg, 0.050 mmol, 1.0 equiv.) in anhydrous Toluene (4.0 mL), were successively added donor 86 (127 mg, 0.060 mmol, 1.2 equiv.) and 4A MS (380 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -52 °C. After 5 min, TMSOTf (2.7 pL, 0.015 mmol, 0.3 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -50 to 10 °C. Et3N, was added. The suspension was filtered over Celite, rinsed with DCM (30 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 7:3) to give compound 116 (196 mg, 69%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C3i3H35iClioN5072Si 2857.0324; found 2857.0325.

[0631] [2,3,4,6-Tetra-O-benzyl-a-D-glucopyranosyl-( 1— >3)]-4-O-benzyl-2-CMevulinoyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-(1^3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra- O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)- 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-3,4-di-O- benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-2-O- acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-( 1 — >4)]-6-O-benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl (A-phenyl)trifluoroacetimidate (117).

[0632] The title compound was synthesized from pentadecasaccharide 116 (323 mg, 0.057 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2 + TEA) gave compound 117 (264 mg, 79%, over 2 steps) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C3i8H35iClioF3N6072Si 2921.0309; found 2921.0396.

[0633] 3-Azidopropyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-2-O- levulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-2- O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O-terf- butyldimethylsilyl-«-L-rhamnopyranosyl-( l—>2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl- (1— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L- rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«- L-rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl- (1— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O-benzyl-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (118). To a solution of PTFA donor 117 (252 mg, 0.043 mmol, 1.0 equiv.) in anhydrous Toluene (2.2 mL) was added 4AMS (504 mg). The mixture was stirred at rt for 15 min under Ar and cooled to -60 °C. After 5 min, TfOH (1.2 pL, 0.013 mmol, 0.3 equiv.) was added. After 5 min, azidopropanol (6.0 pL, 0.065 mmol, 1.5 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -60 to 0 °C. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (20 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (Tol / EtOAc 95:5 to 8:2) to give compound 118 (196 mg, 79%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for CsisI^ClioNsC^Si 2877.0403; found 2877.0449. Heterocoupling of donor 2aY / acceptor 3a

[0634] Y, when protected, corresponds to ABCD’ as defined above, and to ABCD once deprotected.

[0635] Allyl 4-O-benzyl-3-O-tert-butyldimethylsilyl-2-O-levulinoyl-«-L-rhamnopyranosyl-

[0636] (1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O- benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-( 1— >2)-4-O-benzyl-3-O- / c / 7-biityldiniethylsilyl-«-l -rhainnopyranosyl-( 1 — >2)-3,4-di-t?-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranoside (119). To a solution of acceptor ABCD (500 mg, 0.335 mmol, 1.0 equiv.) in anhydrous Toluene (9.0 mL), were successively added donor 34 (846 mg, 0.402 mmol, 1.2 equiv.) and 4A MS (1.69 g). The suspension was stirred at rt for 15 min under Arand cooled to -45 °C. After 5 min, TfOH (21 pL, 0.235 mmol, 0.7 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -45 to 0 °C. Et3N was added. The suspension was filtered over Celite, rinsed with DCM (50 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 8:2) to give compound 119 (1063 mg, 93%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for Ci77H2i6Cl8N4O44Si21718.5912; found 1718.5926.

[0637] 4-O-Benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4- di-f>-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl- (1— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-( 1— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl (A-phenyl)trifluoroacetimidate (120). The title compound was synthesized from decasaccharide 119 (1667 mg, 0.489 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2 + TEA) gave compound 120 (1419 mg, 85%, a / p 2: 1, over 2 steps) as a crystalline solid. HRMS (ESI-TOF): m / z [M+NH4]+calcd for Ci82H2i2C18F3N4O44Si2 3551.1500; found 3551.1009.

[0638] Allyl 4-O-benzyl-3-O-terCbutyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl- (1— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O- benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O- / c / 7-butyldiniethylsilyl-«-l -rh:ininopyranosyl-( 1 — >2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranosyl-(l— >2)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-«- L-rhamnopyranosyl-( 1— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4- O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (121). To a solution of acceptor 85 (400 mg, 0.113 mmol, 1.0 equiv.) in anhydrous Toluene (7.0 mL), were successively added donor 120 (222 mg, 0.119 mmol, 1.05 + 1.3 equiv.) and 4A MS (800 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -40 °C. After 5 min, TfOH (3.0 pL, 0.034 mmol, 0.3 + 0.7 equiv.) was added and the reaction mixture was allowed to stir under Ar overnight from -40 °C to rt. Et3N was added. The suspension was filtered over Celite, rinsed with DCM (50 mL) and concentrated under reduced pressure. The crude was directly purified by flash chromatography (Tol / EtOAc 95:5 to 85:15) to give compound 121 (527 mg, 89%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C278H322CliiN5O67Si2 2622.4035; found 2622.4068. 4-O-Benzyl-3-O-terf-butyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl-(l— >2)-3,4- di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl- (1— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O-terf-butyldimethylsilyl-«- L-rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O- chloroacetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2- deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-[2,3,4,6-tetra-O-benzyl-a-D- glucopyranosyl-(l— >3)]-4-O-benzyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-(l— >3)-2-O-acetyl-4-O-(2-naphtylmethyl)-«-L-rhamnopyranosyl- ( 1 — >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl (N- phenyl)trifluoroacetimidate (122). The title compound was synthesized from tetradecasaccharide 121 (526 mg, 0.101 mmol, 1.0 equiv.) according to the general procedure for PTFA activation. Purification by flash chromatography (Tol / EtOAc 95:5 to 8:2 + TEA) gave compound 122 (403 mg, 74%, over 2 steps) as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C283H323CliiF3N6O67Si22688.4031; found 2688.4057.

[0639] 3-Azidopropyl 4-6M)enzyl-3-O- / c / 7-butyldimethylsilyl-2-O-levulinoyl-<z-l - rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O- benzyl-a-D-glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6- O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3- O-terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-O-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranosyl-(l— >2)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-«- L-rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4- O-(2-naphtylmethyl)-«-L-rhamnopyranosyl-( 1— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranoside (123). To a solution of PTFA donor 122 (300 mg, 0.056 mmol, 1.0 equiv.) in anhydrous Toluene (2.8 mL) was added 4A MS (600 mg). The mixture was stirred at rt for 15 min under Ar and cooled to -35 °C. After 5 min, TfOH (2.0 pL, 0.022 mmol, 0.4 equiv.) was added. After 5 min, azidopropanol (7.8 pL, 0.084 mmol, 1.5 equiv.) was added and the reaction mixture was allowed to stir under Ar for 1 h from -35 to 0 °C. Et3N was added. The suspension was filtered over Celite, rinsed with DCM (50 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (Tol / EtOAc 95:5 to 8:2) to give compound 123 (242 mg, 82%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C278H323CliiN8O67Si2 2643.9120; found 2643.9212.

[0640] Heterocoupling of donor 2aY / acceptor 3alb

[0641] Allyl [2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1— >3)]-4-O-benzyl-«-L- rhamnopyranosyl-( 1— >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4-O- (2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-( 1 — >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl- ( 1 — >2)-3,4-di-O-benzyl-«-L-rhamnopyranosyl-( 1 —>3)-2-O-acetyl-4-O-(2-naphtylmethyl)-

[0642] «-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl-( 1— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (124). To a solution of acceptor 84 (180 mg, 0.092 mmol, 1.0 equiv.) in anhydrous Toluene (4.6 mL), were successively added donor 86 (221 mg, 0.106 mmol, 1.15 equiv.) and 4A MS (443 mg). The suspension was stirred at rt for 15 min under Ar and cooled to -42 °C. After 5 min, TMSOTf (5.0 pL, 0.028 mmol, 0.3 equiv.) was added and the reaction mixture was allowed to stir under Ar from -40 to 5 °C for 1 h. EtsN was added. The suspension was filtered over Celite, rinsed with DCM (30 mL) and concentrated under reduced pressure. The crude was purified by flash chromatography (cHex / EtOAc 95:5 to 75:25) to give compound 124a (323 mg, 91%), as a crystalline solid. HRMS (ESI-TOF): m / z [M+2NH4]2+calcd for C217H240CI6N4O49 1947.7266; found 1947.7320. The title compound was synthesized from the obtained decasaccharide 124a (399 mg, 0.103 mmol, 1.0 equiv.) according to the general procedure for the preparation of acceptors. Purification by flash chromatography (TolZEtOAc 95:5 to 85: 15) gave compound 124 (397 mg, quant.) as a crystalline solid. HRMS (ESI-TOF): m / z [M+NH4]+calcd for C212H230CI6N3O47 3779.3825; found 3779.3888.

[0643] Allyl 4-O-benzyl-3-O-terCbutyldimethylsilyl-2-CMevulinoyl-«-L-rhamnopyranosyl- (1— >2)-3,4-di-f>-benzyl-«-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f?-benzyl-a-D- glucopyranosyl-(l— >4)]-2-O-chloroacetyl-«-L-rhamnopyranosyl-( 1— >3)-4,6-O- benzylidene-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-4-O-benzyl-3-O- terf-butyldimethylsilyl-«-L-rhamnopyranosyl-(l— >2)-3,4-di-f?-benzyl-«-L- rhamnopyranosyl-( 1— >3)-2-O-chloroacetyl-4-O-(2-naphtylmethyl rhamnopyranosyl-(l—>3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido- / ?-D- glucopyranosyl-(l— >2)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >3)]-4-O-benzyl-«- L-rhamnopyranosyl-( 1— >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1— >3)-2-O-acetyl-4- f>-(2-naphtylmethyl)-«-L-rhamnopyranosyl-(l— >3)-4,6-O-benzylidene-2-deoxy-2- trichloroacetamido- / ?-D-glucopyranosyl-(l— >2)-3,4-di-f>-benzyl-«-L-rhamnopyranosyl- ( 1 — >2)-3,4-di-f2-benzyl-«-L-rhamnopyranosyl-( 1 —>3)-2-O-acetyl-4-O-(2-naphtylmethyl)- «-L-rhamnopyranosyl-(l— >3)-[2,3,4,6-tetra-f2-benzyl-a-D-glucopyranosyl-(l— >4)]-6-O- benzyl-2-deoxy-2-trichloroacetamido- / ?-D-glucopyranoside (125). To a solution of acceptor 124 (202 mg, 0.054 mmol, 1.0 equiv.) in anhydrous Toluene (2.7 mL), were successively added donor 120 (323 mg, 0.091 mmol, 1.7 + 1.0 equiv.) and 4A MS (443 mg). The suspension was stirred at rt for 15 min under Ar. Then, the reaction flask was and cooled to -40 °C. After 5 min, TMSOTf...

Claims

1. CLAIMS1. A tetrasaccharide compound of following formula (O):wherein:R is (9-allyl (O-All), (9-triisopropylsilyl (O-TIPS), (9-tert-butyldiphenylsilyl (O-TBDPS), O- ZcW-butyldimethyl silyl (O-TBS or (9-TBDMS), (9-thexyl dimethyl silyl (O-TDS), O-para- methoxyphenyl (O-PMP) or SRo, with Ro being such as the compound is a thioglycoside, said Ro being for example phenyl, tolyl, ethyl, CH2-(te / 7-butyl-Ph) or 2-tert-butyl-5-methylphenyl; R’ is NHC(O)CC13, NHC(O)CHC12, NAC2, NHTroc with Troc being 2,2,2- trichloroethoxycarbonyl, a residue comprising a NHC(O)O function such as NHCbz, with Cbz being carboxybenzyl, NAlloc, with Alloc being allyloxy carbonyl, NHC(O)CF3, tetrachlorophtalimido, phtalimido, or azido;Ri is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac), and R2is levulinoyl (Lev), fluorenylmethoxycarbonyl (Fmoc), or pentafluorophenyl ester (PFP); or R2is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac), and Ri is levulinoyl (Lev), fluorenylmethoxycarbonyl (Fmoc), or pentafluorophenyl ester (PFP);R4, Rs and Re are independently chosen from arylmethyl protecting groups, in particular benzyl (Bn), / % / ra-chlorobenzyl (PCB), / % / ra-bromobenzyl (PBB), / % / ra-nitrobenzyl or ortho- nitrobenzyl;R3, R7 and FWR9 are protecting groups that are orthogonal to each other and orthogonal to R, Ri, R2, R4, Rs, Re and R’.

2. A tetrasaccharide compound of following formula (Io):wherein:R is (9-allyl (O-All), (9-triisopropylsilyl (O-TIPS), (9-tert-butyldiphenylsilyl (O-TBDPS), O- tert-butyldimethylsilyl (O-TBS or (9-TBDMS), (9-thexyl dimethyl silyl (O-TDS), O-para- methoxyphenyl (O-PMP) or SRo, with Ro being such as the compound is a thioglycoside, said Ro being for example phenyl, tolyl, ethyl, CH2-( / crt-butyl-Ph) or 2-tert-butyl-5-methylphenyl; Ri is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac), and R2 is levulinoyl (Lev), fluorenylmethoxycarbonyl (Fmoc), or pentafluorophenyl ester (PFP); or R2 is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac), and Ri is levulinoyl (Lev), fluorenylmethoxycarbonyl (Fmoc), or pentafluorophenyl ester (PFP);R3 is tert-butyl dimethyl silyl (TBS), triethylsilyl (TES), triisopropyl silyl (TIPS), 2- methylnaphthyl (Nap), / % / ra-methoxybenzyl (PMB), / % / ra-bromobenzyl (PBB), para- chlorobenzyl (PCB), / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, 2-pyridylmethyl (picolinyl), picoloyl ester (pico), or allyl (All);R4, Rs and Re are independently chosen from arylmethyl protecting groups, in particular benzyl (Bn), / % / ra-chlorobenzyl (PCB), / % / ra-bromobenzyl (PBB), / % / ra-nitrobenzyl or ortho- nitrobenzyl, R4, Rs and Re being in particular Bn;R7 is 2-methylnaphthyl (Nap), para-m ethoxybenzyl (PMB), / % / ra-bromobenzyl (PBB), para- chlorobenzyl (PCB), tert-butyldimethyl silyl (TBS), triethylsilyl (TES), triisopropyl silyl (TIPS), / % / ra-nitrobenzyl, ortAo-nitrobenzyl, 2-pyridylmethyl (picolinyl), picoloyl ester (pico), allyloxycarbonyl (Alloc) or allyl (All); none or only one of R, OR3 and OR7 being OA11;R7 being different from PBB and PCB when at least one of R4, Rs and Re is PBB or PCB; with R3 being TBS or TES, and R being different from TIPS, TBDPS, TBS and TDS, when R7 is Nap, PMB or PBB, with R3 being Nap, PMB or PBB when R7 is TBS or TES, and R being different from TIPS, TBDPS, TBS and TDS;with R3 being Nap and R7 being PMB or PBB, or R7 being Nap and R3 being PMB or PBB, when R is TIPS, TBDPS, TBS or TDS, with R3 being TBS, TES, TIPS, PMB, PCB, PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R7 is Nap, and R3 being Nap, PMB, PCB or PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R7 is TBS, TES, or TIPS; and with R7 being TBS, TES, TIPS, PMB, PCB, PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R3 is Nap, and R7 being Nap, PMB, PCB or PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R3 is TBS, TES, or TIPS;Rs and R9 form together a benzylidene acetal (Bzl), cyclohexylidene acetal or isopropylidene acetal, or, when R3 and R7 are not Nap, / % / ra-nitrobenzylidene acetal or naphthylidene acetal, or silylidene (DTBS), when none of R3 and R7 is TBS, TES, or TIPS, in particular TBS; or of following formula (I):(I), wherein:All is allyl;Ri is chloroacetyl (CA), bromoacetyl (BA), or acetyl (Ac);R2 is levulinoyl (Lev) or fluorenylmethoxycarbonyl (Fmoc) or pentafluorophenyl ester (PFP), in particular Lev or Fmoc, even more particularly Lev;R3 is / c / 7-butyl di methyl silyl (TBS), triethylsilyl (TES), 2-methylnaphthyl (Nap), para- methoxyphenyl (PMB) or / % / ra-bromobenzyl (PBB);R4, Rs and Re are independently chosen from arylmethyl protecting groups, in particular benzyl (Bn), / % / ra-chlorobenzyl (PCB), / % / ra-bromobenzyl (PBB), / % / ra-nitrobenzyl or ortho- nitrobenzyl;R7 is 2-methylnaphthyl (Nap), / % / ra-methoxyphenyl (PMB), / % / ra-bromobenzyl (PBB), tert- butyldimethyl silyl (TBS) or tri ethylsilyl (TES);R7 being different from PBB and PCB when at least one of R4, Rs and Re is PBB or PCB;with R3 being TBS or TES, and R being different from TIPS, TBDPS, TBS and TDS, when R7 is Nap, PMB or PBB, with R3 being Nap, PMB or PBB when R7 is TBS or TES, and R being different from TIPS, TBDPS, TBS and TDS; with R3 being Nap and R7 being PMB or PBB, or R7 being Nap and R3 being PMB or PBB, when R is TIPS, TBDPS, TBS or TDS, with R3 being TBS, TES, TIPS, PMB, PCB, PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R7 is Nap, and R3 being Nap, PMB, PCB or PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R7 is TBS, TES, or TIPS; and with R7 being TBS, TES, TIPS, PMB, PCB, PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R3 is Nap, and R7 being Nap, PMB, PCB or PBB, / % / ra-nitrobenzyl, ort / 20-nitrobenzyl, picolinyl, or pico, when R3 is TBS, TES, or TIPS;Rs and R9 form together a benzylidene acetal (Bzl), cyclohexylidene acetal or isopropylidene acetal, or, when R3 and R7 are not Nap, / % / ra-nitrobenzylidene acetal or naphthylidene acetal, or silylidene (DTBS), when none of R3 and R7 is TBS, TES, or TIPS, in particular TBS, or of following formula (Ii):wherein:All is allyl;CA is chloroacetyl;Lev is levulinoyl;TBS is terLbutyldimethylsilyl;Bn is benzyl;Nap is 2-methylnaphthyl.

3. A process of preparation of a compound according to claim 2, comprising a step of contacting a donor of formula (IA) with an acceptor of formula (IB) to yield said compound of formula (I), said formula (IA) being as follows:(IA),Wherein:G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA) or trichloroacetimidyl (TCA);R1-R7 being as defined in claim 1 or 2; said formula (IB) being as follows:R88(jS^L~OAiiNHC(O)CCI3 (Ib)R8-R9 being as defined in claim 1 or 2.

4. A penta- or hexasaccharide compound of following formula (II):wherein: one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; or Rs represents a-D-Glc / ?-(l— >2)-a-D-Glcp; the other R1-R7 groups are as defined above; when Rs represents a protected residue a-D-Glcp- or a-D-Glcp-(l— >2)-a-D-Glcp, R’9 is a protecting group to which All, R2, R3 and R7 are orthogonal, and R3 may also represent Bn; and when Rs does not represent a protected residue a-D-Glcp- or a-D-Glc / ?-(l— >2)-a-D-Glc / ?, Rs and R’9 form together a benzylidene acetal (Bzl) or isopropylidene acetal.

5. A penta- or hexasaccharide compound of following formula (II):wherein: one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; the other R1-R7 groups are as defined in claim 1; when Rs represents a protected residue a-D-Glcp-, R’9 is chosen from Bn, Nap, PMB, PBB, and, when R3 is not TBS or TES, TBDPS, TES, TBS and thexyl (TDS), notably TBDPS and TES, and wherein R3 may also represent Bn, and when Rs does not represent a protected residue a-D-Glcp-, Rs and R’9 form together a benzylidene acetal (Bzl), cyclohexylidene acetal or isopropylidene acetal, or, when R3 and R7 are not Nap, / wa-nitrobenzyli dene acetal or naphthylidene acetal.

6. A process of preparation of a pentasaccharide SFlb’-OAll according to claim 5, wherein:, D is 3)-a-D-GlcpNAc-(l^- or 3)-P-D-G1C / ?NAC-(1^- , E represents a residue a-D-Glcp-;SFlb being in particular O-acetylated in position 2c; and’ denotes that the pentasaccharide is protected as defined below, said process comprising the following steps:(i) A step of deprotection of the Rs group of a compound of formula (I), in particular by deprotecting both Rs and R9 using for example SnCh, camphorsulfonic acid (CSA) or trifluoroacetic acid (TFA), and then by protecting the obtained compound with a R’9 group using for example RVBr and Taylor reagent, RVBr with Bu2SnO activation, R’9-TCA or R’9-PTFA, R’9 being as defined above, to obtain an acceptor compound of following formula:wherein R1-R7 and R’9 are as defined above;(ii) A step of reacting the acceptor obtained in step (i) with the donor compound E-OG of following formula:wherein:Pi, P2, P3 and P4 are independently chosen from arylmethyl protecting groups, in particular Bn, PCB, PBB, PMB, / % / ra-nitrobenzyl or ort / zo-nitrobenzyl, and Nap,G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), to yield the pentasaccharide SFlb’-OAll of following formula:Wherein R1-R7 and R’9, Pi, P2, P3 and P4 are as defined above; or of a pentasaccharide SF2a’-OAll according to claim 5, wherein:, E represents a residue a-D-Glcp-; and’ denotes that the pentasaccharide is protected as defined below, said process comprising the following steps:(i) A step of deprotection of the R7 group of a compound of formula (I), for example using 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (DDQ) and optionally P-pinene when R7 is Nap, to obtain an acceptor compound of following formula:wherein Ri-Re and R8-R9 are as defined above;(ii) A step of reacting the acceptor obtained in step (i) with the donor compound E-OG of following formula:wherein:Pi, P2, P3 and P4 are as defined above,G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), to yield the pentasaccharide SF2a’-OAll of following formula:wherein Ri-Re, R8-R9, Pi, P2, P3 and P4 are as defined above; or of an hexasaccharide SF2b’-OAll according to claim 5, wherein:SF2b is (E)AB(E)CD, with A is 2)-a-L-Rha / ?-(l^ , B is 2)-a-L-Rha / ?-(l^ , C is 3)-a-L-Rha / >- (1— > , D is 3)-a -D-G1C / ?NAC-(1^- or 3)-P-D-G1C / ?NAC-(1^ , E represents a residue a-D-Glcp- ; and’ denotes that the hexasaccharide is protected as defined below, said process comprising the following steps:(i) A step of deprotection of the R7 group of a compound of formula (I), for example using 2,3-dichloro-5,6-dicyano— 1,4-benzoquinone (DDQ) and optionally P-pinene when R7 is Nap, to obtain an acceptor compound of following formula:wherein Ri-Re and R8-R9 are as defined above;(ii) A step of reacting the acceptor obtained in step (i) with the donor compound E-OG of following formula:wherein:Pi, P2, P3 and P4 are as defined above,G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), in particular in presence of an additive, for example N,N-di methyl form am ide (DMF),(iii) A step of deprotection of the R3 group of the compound obtained in step (ii), for example using tri ethylamine trihydrofluoride (TEA.3HF) when R3 is TBS, to obtain an acceptor compound of following formula:wherein R1-R2, and R4-R9 are as defined above;(iv) A step of reacting the acceptor obtained in step (i) with the donor compound E-OG of following formula:wherein:Pi, P2, P3 and P4 are as defined above,G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), in particular in presence of an additive, for example A,A-di methyl form am ide (DMF), or (i) A step of deprotection of the R3 group of a compound of formula (I), for example using triethylamine trihydrofluoride (TEA.3HF) when R3 is TBS, to obtain an acceptor compound of following formula:wherein R1-R2, and R4-R9 are as defined above;(ii) A step of reacting the acceptor obtained in step (i) with the donor compound E-OG of following formula:wherein:Pi, P2, P3 and P4 are as defined above,G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), in particular in presence of an additive, for example N,N-di methyl form am ide (DMF),(iii) A step of deprotection of the R7 group of a compound obtained in step (ii), for example using 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (DDQ) and optionally P-pinene when R7 is Nap, to obtain an acceptor compound of following formula:wherein R1-R2, R4-R6 and R8-R9 are as defined above; (iv) A step of reacting the acceptor obtained in step (i) with the donor compound E-OG of following formula:wherein:Pi, P2, P3 and P4 are as defined above,G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), in particular in presence of an additive, for example A,A-dimethylformamide (DMF), to yield the hexasaccharide SF2b’-OAll of following formula:wherein R1-R2, R4-R6, R8-R9, Pi, P2, P3 and P4 are as defined above; or of a pentasaccharide SF3a’-OAll according to claim 5, wherein:, D is 3)-a-D-GlcpNAc-(l^- or 3)-P-D-G1C / ?NAC-(1^- , E represents a residue a-D-Glcp- ;SF3a being in particular O-acetylated in position 2c, or not O-acetylated in position 2c (corresponding to SFX); and ’ denotes that the pentasaccharide is protected as defined below, said process comprising the following steps:(i) A step of deprotection of the R3 group of a compound of formula (I), for example using triethylamine trihydrofluoride (TEA.3HF) when R3 is TBS, to obtain an acceptor compound of following formula:wherein R1-R2, and R4-R9 are as defined above;(ii) A step of reacting the acceptor obtained in step (i) with the donor compound E-OG of following formula:wherein:PI, P2, P3 and P4 are as defined above,G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), to yield the pentasaccharide SF3a’-OAll of following formula:wherein R1-R2, R4-R9, Pi, P2, P3 and P4 are as defined above.

7. A penta- or hexasaccharide acceptor compound of following formula (IIIA):wherein: one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; in particular Rs, R7 or R3 representing a protected residue a-D-Glcp-; the other Ri, R3-R8 and R’9 being as defined above.

8. A process of preparation of a penta- or hexasaccharide acceptor compound of formula (IIIA) according to claim 7, comprising a step of deprotection of group R2 of a compound of formula (II), in particular using hydrazine acetate or hydrazine in a mixture pyridine / acetic acid, in particular in a 1 : 1 (v / v) pyridine / acetic acid mixture when R2 is Lev.

9. A penta- or hexasaccharide compound of following formula (IIIDHF):wherein:Q is H, G or LZ,G is an activating group, in particular A-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA),L, which is optionally protected is: a single bond,a divalent C1-C12 alkyl chain optionally interrupted by one or more heteroatoms, notably selected from an oxygen atom, a sulphur atom or a nitrogen atom, said nitrogen and sulphur atoms being optionally oxidized, and the nitrogen atom being optionally involved in an acetamide bond, or a divalent C1-C12 alkyl chain substituted by at least one -OH group, being in particular of the following formula -(CH2-CH2-C(OH))q-(CH2-CH2)i, wherein i is 0 or 1 and q ranges from 1 to 10,Z is a terminal function or group, optionally protected, able to form a covalent bond with a compound enabling to extend said LZ chain, a carrier and / or a solid support, or a multivalent scaffold; an anchor; a mono-, oligo- or polysaccharide; or a dye or fluorescent residue in particular a pentasaccharide donor compound of following formula (IIID):wherein:G is an activating group, in particular TV-phenyltrifluoroacetimidyl (PTFA), or trichloroacetimidyl (TCA), one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; in particular Rs, R7 or R3 representing a protected residue a-D-Glcp-; the other Ri-Rs and R’9 groups are as defined above; or in particular a penta- or hexasaccharide compound of following formula (IIIH):(IIIH), wherein: one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; in particular Rs, R7 or R3 representing a protected residue a-D-Glcp-; the other Ri-Rs and R’9 groups are as defined above; or in particular a functionalized penta- or hexasaccharide compound of following formula (IHF):(IIIF), wherein:L and Z are as defined above; one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; in particular Rs, R7 or R3 representing a protected residue a-D-Glcp-; the other Ri-Rs and R’9 groups are as defined above, or in particular a functionalized penta- or hexasaccharide acceptor compound of following formula (IIIAF):(HIAF), wherein one or two of Rs, R7 and R3 represent(s) a protected residue a-D-Glcp-; in particular Rs, R7 or R3 representing a protected residue a-D-Glcp-; the other Ri-Rs and R’9 groups, L and Z are as defined above.

10. A process of preparation of: a penta- or hexasaccharide donor compound of formula (IIID) according to claim 9, comprising a first step of deprotection of the All group, in particular using PdCL and then N- iodosuccinimide (NIS), or using iridium, to obtain a compound of formula (IIIH), and a second step of contacting the obtained compound with a compound of type G-LG wherein G is as defined in claim 5, and LG is a leaving group, for example PTFA-C1 when G is PTFA, or a functionalized penta- or hexasaccharide compound of following formula (IIIF), comprising a step of contacting a penta- or hexasaccharide donor compound of formula (IIID) with a compound of formula HO-LZ’, wherein Z’ is Z, optionally protected, or a group enabling to form Z, in particular in presence of TMSOTf, TfOH, TBSOTf, AgOTf, TfzO, Bi(OTf)3, Yb(OTf)3, L / EtsSiH, TMSB(C6Fs)4, acid-washed molecular sieves, ZnBr2, or BF3-Et2O, notably in catalytical conditions, or of a functionalized penta- or hexasaccharide acceptor compound of following formula (IIIAF), comprising a step of deprotection of the group R2 of a compound of formula (IIIF), in particular using hydrazine acetate or hydrazine in a mixture pyridine / acetic acid, in particular in a 1 : 1 (v / v) pyridine / acetic acid mixture when R2 is Lev.

11. A polysaccharide compound of formula R2-P’-OQ’, wherein P’ is constituted of or comprises at least two units, and in particular at most nine or ten units, chosen from -SFlb’-, - SF2a’-, -SF2b’- and / or -SF3a’- of following formulae:being in particular Ac, more particularly with P’ being constituted of or comprising at least two units chosen from -SFlb’-, -SF2a’-, - SF2b’- and -SF3a’-, at least two of these units being different,-SF3a’-, Ri being in particular Ac, more particularly with P’ being constituted of or comprising at least two units chosen from -SFlb’-, -SF2a’-, -SF2b’- and -SF3a’-, at least two of these units being different, wherein R1-R9 and R’9, Pi, P2, P3, and P4 are as defined above, and wherein Q’ is H, All, or LZ as defined above.

12. The polysaccharide compound according to claim 11, wherein P’ is constituted of or comprises at least two units chosen from -SFlb’-, -SF2a’-, -SF2b’-, -SF3a’- and -ABCD’- (corresponding to -SFY’-) of following formula:wherein Ri and R3-R9 are as defined above,P’ comprising at least one unit, in particular at least two units chosen from -SFlb’-, -SF2a’-, - SF2b’-, -SF3a’-, and at least one and -ABCD’- unit (-SFY’- unit), in particular one -ABCD’- unit, more particularly between two units chosen from -SFlb’-, -SF2a’-, -SF2b’-, -SF3a’-.

13. A process of preparation of a polysaccharide as defined in claim 11 or 12, comprising:a) a step of contacting a penta- or hexasaccharide acceptor compound of formula (IIIA) or (IIIAF), or a ABCD acceptor, and a penta- or hexasaccharide donor compound of formula (IIID) or a ABCD donor; and optionally: b) a step: of converting the polysaccharide obtained in a previous step into an acceptor by deprotecting the R2 group, in particular using hydrazine acetate or hydrazine in a mixture pyridine / acetic acid, in particular in a 1 : 1 (v / v) pyridine / acetic acid mixture when R2 is Lev; or of converting the polysaccharide obtained in a previous step into a donor by first deprotecting the All group, in particular in particular using PdCL and then NIS, and then of contacting the obtained compound with a compound of type D’-LG wherein D’ is a donor group and LG is a leaving group, for example PTFA-C1 when D’ is PTFA; and c) a step of contacting the acceptor or donor obtained in step b) with a penta- or hexasaccharide donor compound of formula (IIID) or a ABCD donor; or a penta- or hexasaccharide acceptor compound of formula (IIIA) or (IIIAF) or a ABCD acceptor, respectively, or an acceptor or donor obtained in one of the previous steps, respectively; step b) and c) being repeated if necessary; and / or d) a step of functionalizing if necessary the polysaccharide obtained in a previous step by deprotecting the All group, in particular using PdCh and then NIS, contacting the obtained compound with a compound of type D’-LG wherein D’ is a donor group and LG is a leaving group, for example PTFA-C1 when D’ is PTFA, and then contacting the obtained donor with a compound of formula HO-LZ, in particular in presence of TMSOTf, TfOH, TBSOTf, AgOTf, Tf2O, Bi(OTf)3, Yb(OTf)3, I2 / Et3SiH, TMSB(C6FS)4, acid-washed molecular sieves, ZnBr2, or BF3-Et2O, notably in catalytical conditions; step d) taking place after step c), or after one of steps c) if step c) is repeated), in particular after last step c).

14. A process of preparation of a glycoconjugate of formula H-P-OLZ’, wherein:P is constituted of or comprises at least two units chosen from -SFlb-, -SF2a-, -SF2b-, -SF3a- and -ABCD- (corresponding to -SFY-), wherein:SFlb is ABC(E)D, SF2a is AB(E)CD, SF2b is (E)AB(E)CD SF3a is (E)ABCD, with A is 2)- a-L-Rha / ?-(l^ , B is 2)-a-L-Rha / ?-(l^ , C is 3)-a-L-Rha / ?-(l^ , D is 3)-P-D-G1C / ?NAC-(1^, or, when D is in terminal position, 3)-P-D-GlcpNAc-(l^- or 3)-a-D-GlcpNAc-(l^- , E represents a residue a-D-Glcp-;L is: a single bond, a divalent C1-C12 alkyl, C2-C12 alkenyl or C2-C12 alkynyl chain optionally interrupted by one or more heteroatoms, notably selected from an oxygen atom, a sulphur atom or a nitrogen atom, said nitrogen and sulphur atoms being optionally oxidized, and the nitrogen atom being optionally involved in an acetamide bond, or a divalent C1-C12 alkyl, C2-C12 alkenyl or C2-C12 alkynyl chain substituted by at least one -OH group, being in particular of the following formula -(CH2-CH2-C(OH))q- (CH2-CH2)i, wherein i is 0 or 1 and q ranges from 1 to 10,Z’ is Zi or F1-L2-Z2,Zi is a terminal function or group, optionally protected, able to form a covalent bond with a carrier and / or a solid support, or a multivalent scaffold; an anchor; a mono-, oligo- or polysaccharide; or a dye or fluorescent residue.Fi is any group enabling to bond the linker L to the linker L2, Fi being in particular chosen from the -C(O)-, -C(O)-C(O)-, -C(O)-C(O)-NH-, -NHC(O)-C(O)-, -NHC(O)-C(O)-NH-, -C(O)- C(H)=N-NH-, -NH-C(O)-C(H)=N-NH-, ester, amide, amine, -CH2-, ether, thioether, imine, thio-succinimide, oxime, hydrazone, hydrazonamide, -C(0)CH2-NH-, -NH-CH2-C(0)-, triazole functions or groups, and from the following:single bond, divalent C1-C12 alkyl, C2-C12 alkenyl or C2-C12 alkynyl chain optionally interrupted by one or more heteroatoms, notably selected from an oxygen atom, a sulphur atom or a nitrogen atom, said nitrogen and sulphur atoms being optionally oxidized, and the nitrogen atom being optionally involved in an acetamide bond,Z2 is Zi or F2-L3-Zi,F2 is any group enabling to bond the linker L to the linker L3, Fi being in particular chosen from the -C(O)-, -C(O)-C(O)-, -C(O)-C(O)-NH-, -NHC(O)-C(O)-, -NHC(0)-C(0)-NH-, -C(O)- C(H)=N-NH-, -NH-C(O)-C(H)=N-NH-, ester, amide, amine, -CH2-, ether, thioether, imine, thio-succinimide, oxime, hydrazone, hydrazonamide, -C(O)CH2-NH-, -NH-CH2-C(O)-, triazole functions or groups, and from the following:single bond, a divalent C1-C12 alkyl,C2-C12 alkenyl or C2-C12 alkynyl chain optionally interrupted by one or more heteroatoms, notably selected from an oxygen atom, a sulphur atom or a nitrogen atom, said nitrogen and sulphur atoms being optionally oxidized, and the nitrogen atom being optionally involved in an acetamide bond, said process comprising: a) One or more steps of full deprotection of a polysaccharide of formula R2-P’-LZ as defined above, to obtain a H-P-OLZi compound or a H-P-OLFi compound, L and Zi being as defined above, Ff being a precursor of Fi as defined above; b) Optionally, a step of contacting the fully deprotected polysaccharide obtained in the previous step with:- a compound of following formula FI”-L2-ZI, Fi” being a precursor of Fi as defined above, L2 and Zi being as defined above, or- a compound of following formula FI”-L2-F2’, Fi” being a precursor of Fi as defined above, F2’ being a precursor of F2 as defined above, L2 being as defined above, followed by contacting the obtained compound with a compound of following formula F2”-L3-ZI, wherein F2” is a precursor of F2 as defined above, and L3 and Zi being as defined above,15. A glycoconjugate of formula H-P-OLZ’, as defined above, wherein P is constituted of or comprises: at least two different units chosen from -SFlb-, -SF2a-, -SF2b-, -SF3a-; at least one -SFlb- unit, with LZ’ being different from propyl when P is constituted of or comprises one -SFlb- unit; or at least one -ABCD- unit (-SFY- unit), in particular one -ABCD- unit, and at least one unit chosen from -SFlb-, -SF2a-, -SF2b-, -SF3a-, andAnd wherein:- the ABCD units are optionally substituted by at least one phosphoethanolamine (PEtN-modified); and / or the units, in particular the -SFlb-, -SF2a-, -SF2b-, -SF3a- units are optionally acetylated, said acetylation being partial or stoichiometric, -SF3a- being in particular stoichiometrically acetylated in position 2c, or not (9-acetylated in position 2c (corresponding to SFX), -SFlb- being in particular acetylated, more particularly partially, in position 2c.

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