Process for preparation of one or more C-glycoside derivatives comprising catalytic reduction stage

Abstract

The present invention relates to a process for the preparation of one or more C-glycoside derivatives corresponding to formula (I), preferably corresponding to formula (I '), and the optical isomers, geometric isomers and / or solvates thereof, such as hydrates, comprising at least one purification stage carried out in an aqueous medium. The invention also relates to a process for the preparation of one or more C-glycoside derivatives corresponding to formula (I 'B), comprising a reduction stage of at least one compound of formula (I), preferably of formula (I'), carried out in an aqueous medium.

Description

Technical Field

[0001] The present invention relates to a method for preparing one or more C-glycoside derivatives corresponding to formula (I) as described below, preferably corresponding to formula (I') or (I''), and their optical isomers, geometric isomers, and / or solvates such as hydrates, comprising at least one purification stage carried out in an aqueous reaction medium.

[0002] The present invention also relates to a method for purifying at least one aqueous reaction medium comprising at least one C-glycoside derivative corresponding to formula (I) and at least one impurity of formula (IV), as described below. Background Technology

[0003] Methods for synthesizing water-soluble organic surfactants with favorable cosmetic properties can lead to the formation of impurities in ionic form, which are often proven difficult to minimize, or even remove, without significantly affecting the yield of the final cosmetic active compound.

[0004] Furthermore, when such impurities are present alongside the final cosmetic active compound, they can produce undesirable changes in color, texture, or odor in cosmetic compositions employing said active agents. Thus, such impurities can be a source of unpleasant and noticeable odors, such as a pungent and strong vinegar smell, which readily manifests itself even after several purification processes and proves inconvenient and persistent even after formulation for consumers, especially given the current trend of using less and less fragrance in cosmetic products to mask or neutralize this type of odor.

[0005] Such impurities may also cause compatibility issues with other additives that may be present in the final cosmetic formulation.

[0006] Such impurities can also be salts of acids or bases, which will affect the pH of the aqueous medium. This effect is even more problematic when cosmetic surfactants are separated in the form of concentrated aqueous solutions.

[0007] Furthermore, the presence of such impurities, particularly inorganic and / or organic salts, can cause a significant increase in the viscosity of aqueous reaction media containing cosmetic surfactants, thus making it difficult in some cases to obtain concentrated solutions of cosmetic surfactants intended for use in formulations.

[0008] For example, C-glycoside derivatives are water-soluble organic compounds whose properties are generally advantageous in the cosmetic field, particularly in skincare compositions, for stimulating the synthesis of glycosaminoglycans present in the dermis and, in particular, providing density and firmness to the skin (see, for example, a product titled Pro-Xylane).TM Synthesis of Pro-Xylane in Aqueous Media TM : A New Biologically Active C-glycoside inAqueous Media), M. Dalko-Csiba et al., Bioorganic & Medicinal Chemistry Letters Medicinal Chemistry Letters) , 19 (2009), 845–849 scientific papers.

[0009] C-glycoside derivatives, such as xylose C-glycoside derivatives, are typically synthesized using a reaction known as the Lubineau reaction (Rodrigues, F., Canac, Y. and Lubineau, A., A Convenient, One-Step Synthesis of β-Glycosidic Ketones in Aqueous Media). Chemical Communications , 2000 (20), 2049-2050) are synthesized in an aqueous medium in the presence of an alkaline agent from unprotected monosaccharides or polysaccharides (e.g., D-xylose) and β-dicarbonyl compounds (e.g., acetylacetone).

[0010] The Rubino reaction is carried out with at least one alkali (such as sodium bicarbonate or sodium hydroxide) present in equimolar amounts or in excess, preferably in excess, relative to monosaccharides or polysaccharides, and the duration of the reaction can vary from 5 minutes to 20 hours depending on the nature of the alkali and / or reaction parameters (such as concentration and / or temperature).

[0011] However, this synthetic reaction exhibits a major drawback leading to the formation of impurities, particularly in the form of salts, such as organic salts (e.g., sodium acetate), the residual amounts of which can prove significant and difficult to reduce, even with several routine purification and / or washing operations.

[0012] At the end of the reaction, the aqueous reaction medium can be neutralized with at least one, particularly an inorganic acidifier (e.g., hydrochloric acid), in order to convert the organic acid salt into an organic acid, particularly by converting sodium acetate into acetic acid, so that the amount of organic acid can be subsequently reduced to a commercially acceptable level.

[0013] However, neutralizing the reaction medium with at least one inorganic acidifying agent (such as hydrochloric acid) also leads to the formation of salts, particularly sodium chloride, which can be removed by precipitation by adding a water-miscible solvent (such as alcohol, particularly isobutanol or ethanol).

[0014] It is known from the prior art that an immiscible solvent, water, is added at the end of the reaction to wash the aqueous reaction medium, and then, prior to concentration, the aqueous medium is passed through a pre-conditioned acidic resin in the presence of an alcohol. For this purpose, continuous distillation, particularly to remove water, followed by the addition of alcohol, can induce salt crystallization, followed by optional washing operations with several cycles of water addition to reduce the amount of salt to an acceptable level in commercial solutions intended for use in the cosmetic field.

[0015] At the end of these different purification operations, the obtained C-glycoside derivatives can be pure and solvent-free, and are subsequently subjected to hydrogenation in some cases, which is intended to reduce the ketone functional group of the C-glycoside derivative produced from the β-dicarbonyl derivative to obtain the hydroxyl functional group.

[0016] In particular, xylose C-glycoside derivatives such as C-β-D-xylanopyranoside-n-propane-2-one can then be reduced to produce C-β-D-xylanopyranoside-2-hydroxypropane.

[0017] However, such purification procedures (including those performed several times in succession) have not yet made it possible to satisfactorily reduce the impurities generated during the preparation of C-glycoside derivatives, especially on an industrial scale.

[0018] This is because such washing and / or purification operations exhibit the following disadvantages: they must be performed several times to satisfactorily and sufficiently reduce the content of impurities, and when the impurities are foul-smelling, to minimize the odor generated by certain impurities (such as acetic acid), which is unpleasant and should be avoided for cosmetic use. Furthermore, the formation of sodium chloride during the neutralization phase necessitates washing operations (in the case of adding water or organic solvents, particularly alcohols), and optionally distillation operations for proper removal.

[0019] Therefore, such purification operations (not to mention repetitive ones) exhibit the following disadvantages: reduced yield, generation of additional organic effluents, increased number of stages, and / or cumbersome industrial processes aimed at reducing both the content of organic acids, particularly acetic acid, and the content of salts (e.g., sodium chloride) in the final cosmetic surfactant intended for use in cosmetic products.

[0020] Furthermore, the use of organic solvents, particularly (non)polar aprotic organic solvents, during washing operations typically has the following disadvantages: insufficient reduction of impurities and necessitation of additional washing or neutralization operations, and even purification by chromatography and / or crystallization, which may further impair the yield. Such additional operations are cumbersome to perform on an industrial scale. Moreover, residual organic solvent levels can persist in the solution of cosmetic surfactants used in the final cosmetic formulation, which is undesirable.

[0021] As a result, the purification procedures routinely employed in the preparation of C-glycoside derivatives do not produce sufficiently satisfactory yields and purities, especially for industrial-scale manufacturing that is reproducible and robust for use in the cosmetics field.

[0022] In view of the foregoing, there is a genuine need for a new method for the preparation of C-glycoside derivatives that does not exhibit the aforementioned drawbacks, and in particular leads to improved purity and higher yields, and is optimized for industrial-scale production in terms of product quality, number of purification stages, implementation and / or the organic effluents generated. Summary of the Invention

[0023] In other words, one of the objectives of this invention is particularly to provide a method for preparing one or more C-glycoside derivatives, during which impurities are minimized so that the process can be carried out efficiently on an industrial scale for cosmetic applications.

[0024] In particular, one of the objectives of this invention is to provide a method for preparing one or more C-glycoside derivatives, during which impurities (including those capable of generating unpleasant or offensive odors, such as a pungent and strong vinegar smell, particularly generated by the synthesis stage) are minimized so that the process can be carried out efficiently on an industrial scale for cosmetic applications.

[0025] Therefore, the subject of this invention is particularly a method for preparing at least one compound of formula (I):

[0026] (I)

[0027] In equation (I): - SA' represents a monosaccharide group in the form of pyranose and / or furanose and of the L and / or D series, or a polysaccharide group containing up to 20 sugar units, particularly up to 6 sugar units, preferably a monosaccharide, disaccharide, or trisaccharide, more preferably a monosaccharide, said monosaccharide or polysaccharide group being substituted with at least one free hydroxyl group and optionally at least one amine group optionally protected, particularly protected by an acetyl R'-C(Y)-, wherein R' represents a hydrogen atom or a (C1-C6) alkyl group, such as methyl, and Y represents O or S, preferably O. - The bond between SA' and CH2-X is a C-anomeric bond. - X represents a divalent group -C(O)- or -CH(OR)-. - R represents a hydrogen atom, C1-C 10Preferably, it is a C1-C4 alkyl group, such as methyl, or a (C1-C4) alkyl carbonyl group, such as acetyl, preferably with hydrogen atoms. - R1 represents a saturated or unsaturated, straight or branched, cyclic or acyclic, preferably acyclic C1-C 10 Preferably C1-C4, more preferably saturated, especially C1 hydrocarbon chains, And also one of its optical isomers, geometric isomers, and / or its solvates—such as hydrates— The method includes: - Carry out at least one reaction stage (i) according to the following synthetic scheme (A):

[0028] In the synthetic pathway ( A ) middle: R1 and R2 are the same or different, where R2 has the same meaning as R1 in equation (I). SA' has the same meaning as in equation (I), D + It is an organic or inorganic cation generated by an alkaline agent; preferably, D + It is an inorganic cation. The reaction phase (i) is carried out in an aqueous medium in the presence of the following: At least one compound of formula (II), At least one compound of formula (III), and At least one alkali agent, in an equimolar amount or in excess, preferably in excess, relative to the compound of formula (II), So as to result in the formation of at least one compound of formula (IA) and at least one compound of formula (IV), - Optionally, at least the compound of formula (IA) undergoes at least one reaction stage (ii) in a preferably aqueous medium to result in the formation of at least one compound corresponding to the following formula (IB):

[0029] (IB)

[0030] In formula (IB): - SA', R1, and R have the same meanings as in equation (I). - At least one purification (P) of a reaction medium comprising at least a compound of formula (IV) in an aqueous medium, comprising: At least one processing stage (P1) is carried out using at least one cation exchange resin according to the following scheme in order to convert at least the compound of formula (IV) into the compound of formula (IV'):

[0031] The treatment phase (P1) is carried out at a pH strictly below the pKa of the compound of formula (IV') or below the lowest pKa of the compound of formula (IV') (if several exist). The stage (P2) in which at least one compound of formula (IV') is separated from the reaction medium.

[0032] The expression " SA′ and CH 2 The key between -X "(That It is a C-anomeric bond. This should be understood as referring to the portion of the sugar moiety SA′ that is bonded by carbon-carbon C-C bonds (i.e., methylene-). C The sugar SA'-carbon (H2-) is attached to the rest of the molecule via the methylene-CH2- bond, not via the oxygen-carbon OC bond (i.e., not via the methylene-CH2- bond of the sugar SA′-carbon).

[0033] Within the meaning of this invention, SA' comprises a monosaccharide or a polysaccharide SA group comprising up to 20 sugar units as defined above, wherein SA is substituted with at least one free hydroxyl group.

[0034] In other words, SA' has the same meaning as SA and contains at least one free hydroxyl group (-OH).

[0035] Within the meaning of this invention, a compound of formula (IA) is a compound of formula (I), wherein X corresponds to a divalent group -C(O)-.

[0036] Within the meaning of this invention, a compound of formula (IB) is a compound of formula (I), wherein X corresponds to a divalent group -CH(OR)-, and R is as defined above; preferably, R represents a hydrogen atom.

[0037] In other words, the present invention relates to a method for preparing one or more C-glycoside derivatives of formula (I) as described above, comprising at least one purification (P) in an aqueous reaction medium, aimed at at least significantly minimizing the content of ionic impurities of formula (IV) produced by the synthesis stage (i).

[0038] Therefore, the purification stage (P) has the advantage of being flexible during the preparation of at least one compound of formula (I).

[0039] This is because the purification phase (P) can be performed at least once between reaction phases (i) and (ii) and / or after at least one reaction phase (ii).

[0040] According to one embodiment, the purification phase (P) is performed at least once at the end of the reaction phase (i).

[0041] According to another embodiment, the purification phase (P) is performed at least once at the end of the reaction phase (ii).

[0042] According to a specific embodiment, the purification phase (P) is performed at least once at the end of phase (i), and the method of the present invention does not include phase (ii).

[0043] According to another embodiment, the method of the present invention includes at least one stage (i), preferably one stage (i), and at least one stage (ii), preferably one stage (ii), and the purification stage (P) is performed at least once at the end of at least one stage (i), but not at the end of stage (ii).

[0044] According to yet another embodiment, the method of the present invention includes at least one stage (i), preferably one stage (i), and at least one stage (ii), preferably one stage (ii), and the purification stage (P) is performed at least once at the end of at least one stage (ii), but not at the end of stage (i).

[0045] According to another embodiment, the method of the present invention includes at least one stage (i), preferably one stage (i) and at least one stage (ii), preferably one stage (ii), and the purification stage (P) is performed at least once at the end of at least one stage (i) and at least once at the end of at least one stage (ii).

[0046] According to a preferred embodiment, the method of the present invention includes a stage (i) and a stage (ii), and the purification stage (P) is performed at least once at the end of stage (i) but not at the end of stage (ii).

[0047] Therefore, purification (P) is carried out in an aqueous reaction medium, that is, in a reaction medium that does not contain any organic solvents as described below.

[0048] Therefore, the purification (P) according to the present invention does not involve any washing operations using at least one organic solvent as described below.

[0049] Therefore, the method according to the invention enables the implementation of the objectives described above, that is, to produce one or more compounds of formula (I) with high purity in satisfactory yields, while exhibiting industrially optimized implementation, particularly robust and reproducible implementation, especially compared with methods conventionally used in the prior art.

[0050] In particular, the method according to the invention exhibits the advantage of minimizing impurities, including those that typically produce noticeable and unpleasant odors (such as a pungent and strong vinegar smell), which are particularly difficult to remove in conventional methods employed in the prior art.

[0051] More specifically, the treatment phase (P1) is a neutralization phase, which allows for a significant reduction in the amount of salt formed during reaction phase (i), that is, the amount of the compound of formula (IV).

[0052] In other words, the processing stage (P1) allows at least the compound of formula (IV) to be significantly converted into the compound of formula (IV'), and then the separation stage (P2) allows the content of the compound of formula (IV') to be reduced more easily without the need for organic solvents.

[0053] Therefore, the method according to the invention, particularly the purification stage (P), exhibits the advantage of reducing the content of impurities generated by the reaction stage (i) by not using organic solvents, which greatly improves its environmental footprint and is easy to carry out industrially.

[0054] Then, the method according to the invention advantageously makes it possible to reduce the amount of fragrance used to mask or neutralize unpleasant odors that are easily produced during the preparation of cosmetic formulations employing at least one compound of formula (I).

[0055] The method according to the invention also makes it possible to reduce organic effluent at the reactor outlet and limit many of the washing operations that are routinely performed in methods described in the prior art.

[0056] The method according to the invention exhibits particularly greater ease of industrial optimization than conventional methods of the prior art, especially those involving the sequential execution of several operations to minimize impurities as much as possible, which allows for the processing of synthesis reactions and purification in a single reactor of suitable form.

[0057] The method according to the invention eliminates the need for additional purification stages by chromatography and / or crystallization, which are industrially unsuitable and / or may impair yield.

[0058] Therefore, the method according to the invention enables a reduction in the number of purification stages to be performed at the end of the synthesis reaction (i) and / or (ii), thereby reducing the impurity content of compound (I).

[0059] Furthermore, when the method according to the invention employs a reduction stage (ii), performing at least one purification stage (P) or (P1) at the end of stage (i) and before stage (ii) makes it much easier to obtain the compound of formula (I) with very good yield and very good purity, wherein X = -CH(OR)-.

[0060] The method according to the invention also exhibits the advantage of easily controlling the target level of impurities, which makes it possible to obtain several grades of compounds of formula (I) depending on the desired impurity content.

[0061] Therefore, the method according to the invention makes it easier to control the content of impurities.

[0062] Another subject of the present invention is a method for purifying an aqueous medium comprising at least one compound corresponding to formula (I) as defined above and at least one compound as defined above (IV), comprising: At least one processing stage (P1) is carried out using at least one cation exchange resin according to the following scheme in order to convert at least the compound of formula (IV) into the compound of formula (IV'):

[0063] The treatment phase (P1) is carried out at a pH strictly below the pKa of the compound of formula (IV') or below the lowest pKa of the compound of formula (IV') (if several exist), and The stage (P2) in which at least one compound of at least formula (IV') is separated from the reaction medium. At least one reduction stage (ii1) of catalytic hydrogenation carried out in the presence of at least one metal catalyst.

[0064] Other subjects, features, aspects, and advantages of the invention will become even clearer and more apparent after reading the following description and examples.

[0065] In the following text and unless otherwise specified, the limits of the range of values ​​are included within that range, particularly in the expressions “between” and “ranging from… to…”.

[0066] Furthermore, the expression "at least one / kind" used in this specification is equivalent to the expression "one / kind or more / kinds".

[0067] Furthermore, the expression "at least" as used in this specification is equivalent to the expression "greater than or equal to". Finally, in a manner known per se, the term "C" n The "Cn" designation indicates a compound or group that contains "n" carbon atoms in its chemical structure.

[0068] Within the meaning of this invention, the term " Purification (P) "and" Purification stage (P) Use it without distinction.

[0069] Within the meaning of this invention, the term " Alkali "and" Alkalizing agent Use it without distinction.

[0070] The alkalizing agent can be an inorganic alkali, preferably selected from the group consisting of: alkali metal hydroxides and alkaline earth metal hydroxides, such as lithium hydroxide, sodium hydroxide or potassium hydroxide, alkali metal carbonates (bicarbonates) and alkaline earth metal carbonates (bicarbonates), such as sodium carbonate (bicarbonate) or potassium carbonate (bicarbonate), and mixtures thereof.

[0071] The alkalizing agent can be an organic alkalizing agent, preferably selected from the group consisting of: mono(C1-C6)(hydroxy)alkylamines, di(C1-C6)(hydroxy)alkylamines, tri(C1-C6)(hydroxy)alkylamines (preferably tri(C1-C6)(hydroxy)alkylamines), saturated or unsaturated cyclic amines that are aromatic, such as pyridine, or non-aromatic amines optionally substituted with one or more (C1-C4)alkyl groups, such as tetrahydropyridine optionally substituted with one or more (C1-C4)alkyl groups, piperidine optionally substituted with one or more (C1-C4)alkyl groups, or piperazine optionally substituted with one or more (C1-C4)alkyl groups. Preferably, the organic alkalizing agent is an organic amine, especially a tertiary amine, such as a tri(C1-C6)alkylamine.

[0072] Preferably, the alkalizing agent is selected from the group consisting of: alkali metal hydroxides and alkaline earth metal hydroxides, especially sodium hydroxide, alkali metal carbonates and alkaline earth metal carbonates, especially sodium carbonate or potassium carbonate, and organic amines, preferably tertiary amines, such as triethylamine or diisopropylethylamine.

[0073] Preferably, the alkalizing agent is inorganic.

[0074] More preferably, the alkalizing agent is inorganic and selected from the group consisting of: alkali metal hydroxides and alkaline earth metal hydroxides, alkali metal carbonates (hydrogen salts) and alkaline earth metal carbonates (hydrogen salts) and mixtures thereof, especially alkali metal hydroxides and alkaline earth metal hydroxides, particularly sodium hydroxide.

[0075] The acidifying agent that can be used in the method according to the invention is any acidification method known to those skilled in the art, such as bipolar electrodialysis or the addition of an inorganic acidifying agent, particularly an inorganic acid-type inorganic acidifying agent, such as sulfuric acid, phosphoric acid, sulfonic acid or phosphonic acid, H+ + Hal - Acid, wherein Hal represents a halogen atom selected from the group consisting of chlorine, bromine, and iodine, preferably H. + Hal - An acid, wherein Hal preferably represents a chlorine atom; preferably by adding an inorganic acidifying agent, particularly an inorganic acid of the type of inorganic acid, such as sulfuric acid, phosphoric acid, sulfonic acid, or phosphonic acid, H + Hal - Acid, wherein Hal represents a halogen atom selected from the group consisting of chlorine, bromine, and iodine, preferably H. + Hal - Acid, wherein Hal preferably represents a chlorine atom.

[0076] More preferably, the acidifying agent is hydrochloric acid.

[0077] Method for preparing at least one compound of formula (I)

[0078] As indicated above, the method according to the invention includes: - At least one reaction stage (i), which is in an aqueous medium and according to the reaction scheme as described above ( A This is performed in the presence of the following: Preferably, at least one compound of formula (III) is used in an equimolar amount or in excess of the compound of formula (II), and preferably in excess. At least one alkali agent, preferably at least one inorganic alkali agent, in an equimolar amount or excess, preferably in excess, relative to the compound of formula (II). To result in the formation of at least one compound of formula (IA) (i.e., a compound corresponding to formula (I), wherein X corresponds to a divalent group CO-) and at least one compound of formula (IV); - Optionally at least one reaction stage (ii) leading to the formation of at least one compound of formula (IB) (i.e., a compound corresponding to formula (I), where X corresponds to a divalent group -CH(OR)-, and R preferably represents a hydrogen atom), - At least one purification (P) of a reaction medium containing at least a compound of formula (IV) carried out in an aqueous medium, comprising: At least one processing stage (P1) is carried out using at least one cation exchange resin according to the following scheme in order to convert at least the compound of formula (IV) into the compound of formula (IV'):

[0079] The treatment phase (P1) is carried out at a pH value that is strictly below the pKa of the compound of formula (IV') or below the lowest pKa of the compound of formula (IV') (if several exist). The stage (P2) in which at least one compound of formula (IV') is separated from the reaction medium.

[0080] Reaction phase (i)

[0081] Advantageously, reaction phase (i) is carried out in an aqueous medium in the presence of: At least one compound of formula (II), At least one compound of formula (III), Preferably, the molar ratio of the compound of formula (III) to the compound of formula (II) is greater than or equal to 1, preferably between 1 and 5, more preferably between 1 and 4, even more particularly between 1 and 3, even better between 1 and 2, and particularly ranging from 1 to 1.5; according to a specific embodiment, the molar ratio of the compound of formula (III) to the compound of formula (II) is greater than 1. At least one alkali agent, Preferably, at least one alkali agent as described above is used, preferably inorganic, and more preferably selected from the group consisting of: alkali metal hydroxides and alkaline earth metal hydroxides, alkali metal carbonates (hydrogenates) and alkaline earth metal carbonates (hydrogenates), and mixtures thereof; particularly alkali metal hydroxides and alkaline earth metal hydroxides, such as sodium hydroxide. Alkali is used in equimolar amounts or in excess. Preferably, the molar ratio of the alkali agent to the compound of formula (II) is greater than or equal to 1, preferably between 1 and 5, more preferably between 1 and 4, even more particularly between 1 and 3, and even more preferably between 1 and 2; according to a specific embodiment, the molar ratio of the alkali agent to the compound of formula (II) is greater than 1. Preferably, reaction phase (i) is carried out under the following conditions: At temperatures ranging from 20°C to 80°C, preferably from 20°C to 70°C, more preferably from 30°C to 70°C, even more preferably from 30°C to 60°C, and even more preferably from 35°C to 45°C, Preferably, the duration of the reaction varies as follows: From 10 minutes to 10 hours, preferably from 20 minutes to 5 hours, more preferably from 30 minutes to 4 hours, and even more preferably from 45 minutes to 3 hours.

[0082] Preferably, reaction (i) is carried out at atmospheric pressure.

[0083] Preferably, the reaction stage (i) is carried out in an aqueous medium and includes, in sequence: Preferably, at least one compound of formula (II) is added to an aqueous medium, particularly at temperatures varying from 20°C to 80°C. Preferably, at least one compound of formula (III) is added to an aqueous medium containing at least one compound of formula (II). Optionally, before adding at least one alkali agent, the temperature is advantageously reduced by at least 5°C, particularly by at least 10°C, and preferably by at least 20°C. Preferably, as described above, at least one alkali agent (preferably inorganic) is added in an equimolar amount or in excess, preferably in excess, relative to the compound of formula (II), while maintaining a temperature preferably less than or equal to 60°C, more preferably less than or equal to 50°C, and even more preferably less than or equal to 45°C. Preferably, the reaction medium comprising at least one compound of formula (II), at least one compound of formula (III), and at least one alkali is maintained at the temperature at which the addition of at least one alkali ends and / or heated to the reaction temperature as described above. Optionally, at the end of reaction (i), the reaction medium may be cooled to at least 5°C, preferably at least 10°C, more preferably at least 15°C.

[0084] Preferably, at the end of reaction stage (i), the pH can be adjusted to a value less than or equal to 8.5 and greater than or equal to 2.5, preferably within a range extending from 2.5 to 8.5.

[0085] pH can be adjusted by any acidification means known to those skilled in the art, such as using at least one acidic resin and / or by adding at least one acidifying agent as described above, preferably inorganic, more preferably selected from the group consisting of inorganic acids as described above.

[0086] According to a specific embodiment, the pH is adjusted by using at least one acidic resin and optionally by adding at least one acidifying agent as described above, the acidifying agent being preferably inorganic, more preferably selected from the group consisting of inorganic acids as described above.

[0087] According to a preferred embodiment, the method according to the invention includes stage (i).

[0088] Purification stage (P)

[0089] According to the present invention, the purification stage (P) is carried out on an aqueous reaction medium containing at least one impurity of formula (IV).

[0090] Therefore, the purification stage (P) can be performed once or multiple times on an aqueous reaction medium containing at least one impurity of formula (IV).

[0091] According to one embodiment, the purification phase (P1) is performed once or multiple times, and the purification phase (P2) is performed at least once at the end of at least one phase (P1).

[0092] Therefore, purification (P) can be performed on the aqueous reaction medium produced by reaction stage (i) and / or on the aqueous reaction medium produced by at least one reaction stage (ii).

[0093] In other words, purification (P) may be performed at least once between reaction stage (i) and at least one reaction stage (ii), and / or after at least one reaction stage (ii), for example, after one and / or two reaction stages (ii).

[0094] According to one embodiment, the purification phase (P) is performed at least once at the end of the reaction phase (i).

[0095] According to another embodiment, the purification phase (P) is performed at least once at the end of the reaction phase (ii).

[0096] According to a specific embodiment, the purification phase (P) is performed at least once at the end of phase (i), and the method of the present invention does not include phase (ii).

[0097] According to another embodiment, the method of the present invention includes at least one stage (i), preferably one stage (i), and at least one stage (ii), preferably one stage (ii), and the purification stage (P) is performed at least once at the end of at least one stage (i), but not at the end of stage (ii).

[0098] According to yet another embodiment, the method of the present invention includes at least one stage (i), preferably one stage (i), and at least one stage (ii), preferably one stage (ii), and the purification stage (P) is performed at least once at the end of at least one stage (ii), but not at the end of stage (i).

[0099] According to another embodiment, the method of the present invention includes at least one stage (i), preferably one stage (i) and at least one stage (ii), preferably one stage (ii), and the purification stage (P) is performed at least once at the end of at least one stage (i) and at least once at the end of at least one stage (ii).

[0100] According to a preferred embodiment, the method of the present invention includes a stage (i) and a stage (ii), and the purification stage (P) is performed at least once at the end of stage (i) but not at the end of stage (ii).

[0101] According to one embodiment, the purification phase (P1) is performed at least once at the end of the reaction phase (i).

[0102] According to another embodiment, the purification phase (P2) is performed at least once at the end of the reaction phase (ii).

[0103] According to another embodiment, the method of the present invention includes at least one stage (i), preferably one stage (i) and at least one stage (ii), preferably one stage (ii), and a purification stage (P1) is performed at least once at the end of at least one stage (i) and a purification stage (P2) is performed at least once at the end of at least one stage (ii).

[0104] Preferably, purification (P) is carried out at least once between reaction stage (i) and at least one reaction stage (ii).

[0105] In other words, when at least one stage (ii) exists, the purification stage (P) can be performed at least before and / or at least after the reaction stage (ii), preferably at least before the reaction stage (ii).

[0106] Preferably, purification (P) is performed at least once at the end of reaction phase (i).

[0107] When the method comprises several stages (i), at least one purification (P) may be performed at the end of each stage (i), or at least one purification stage (P) may be performed only at the end of the final stage (i).

[0108] The term “purification stage (P) or purification (P) carried out in an aqueous reaction medium” should be understood within the meaning of this invention to mean a purification stage (P) or purification (P) carried out in any aqueous medium (which may be generated by reaction stage (i) and / or at least one reaction stage (ii)) preferably free of any organic solvents, and preferably free of any organic solvents.

[0109] Therefore, purification (P) is carried out in an aqueous reaction medium containing at least one compound of formula (IV) preferably free of any water-miscible organic solvent (i.e., in an aqueous medium free of water-miscible organic solvent).

[0110] In other words, the treatment phase (P1) and the separation phase (P2) are carried out in an aqueous reaction medium that preferably does not contain any water-miscible organic solvent and contains at least one compound of formula (IV) and / or (IV').

[0111] In other words, water-miscible organic solvents are preferably not used in the treatment stage (P1) and separation stage (P2).

[0112] Preferably, purification (P) is carried out in an aqueous reaction medium free of any organic solvents.

[0113] In other words, purification (P) is preferably carried out in water.

[0114] In other words, organic solvents are preferably not used in the processing stage (P1) and the separation stage (P2).

[0115] According to a preferred feature of the invention, the purification (P) does not involve any stage or operation of washing with at least one water-miscible organic solvent, and preferably does not involve any stage or operation of washing with at least one organic solvent.

[0116] More preferably, the purification (P) does not use organic solvents selected from the group consisting of: dichloromethane, diethyl ether, ethanol and mixtures thereof.

[0117] In particular, purification (P) does not use organic solvents selected from the group consisting of: ethanol, methanol, isopropanol, butanol, isobutanol, tert-butanol and mixtures thereof.

[0118] According to one embodiment, the reaction medium of the purification stage (P) does not contain at least one organic solvent as defined above, particularly selected from the group consisting of: dichloromethane, ethanol, methanol, toluene, isopropanol and mixtures thereof, especially dichloromethane, ethanol and mixtures thereof.

[0119] According to one embodiment, purification (P) does not use organic solvents selected from the group consisting of: dichloromethane, diethyl ether, ethanol, methanol, isopropanol, butanol, isobutanol, tert-butanol, toluene, isopropanol, and mixtures thereof.

[0120] More specifically, purification (P) does not employ organic solvents selected from the group consisting of: nonpolar aprotic organic solvents, such as those described above, C1-C3 alcohols, and mixtures thereof.

[0121] Purified (P) Specifically free from organic solvents selected from the group consisting of: heptane, 1,4-dioxane, benzene, xylene, tetrachloroethylene (Cl2C=CCl2), toluene, carbon disulfide (CS2), trichloroethylene (Cl2C=CHCl), diethyl ether (Et2O), isopropyl ether, tert-butyl methyl ether, ethyl acetate (CH3C(O)OEt or AcOEt), butyl acetate, isopropyl acetate, methylpyrrolidone, cyclopentyl methyl ether, ketones (such as methyl ether ketone or methyl isobutyl ketone), methyl propionate, butanol, isobutanol, tert-butanol, pentanol, dimethyl ether (DME), tetrahydrofuran (THF), methyltetrahydrofuran (2-MeTHF), dichloromethane (CH2Cl2), dichloroethane (ClCH2CH2Cl), and mixtures thereof.

[0122] The purified (P) is particularly free of (non)polar aprotic organic solvents, such as nonpolar aprotic organic solvents, which preferably have a dielectric constant in the range of 1 to 11.

[0123] Purified (P) is more specifically free of (non)polar (non)proton organic solvents.

[0124] According to the general features of the invention, the purification stage (P) specifically does not contain at least one stage of the reaction medium produced by stage (i) and / or produced by at least one stage (ii) by washing with at least one organic solvent as defined above.

[0125] Preferably, at the end of reaction stage (i) and / or at the end of at least one reaction stage (ii), the method does not include at least one stage of washing the reaction medium with at least one organic solvent as defined above.

[0126] Therefore, according to an advantage of the invention, no treatment stage (P1) is performed except for at least one stage of washing with at least one organic solvent, preferably at least one organic solvent as defined above.

[0127] Processing phase (P1)

[0128] The treatment stage (P1) of the reaction medium containing at least one compound of formula (IV) is carried out with at least one cation exchange resin, preferably at least one weak cation resin (e.g., a resin having a carboxylic acid active group), and / or at least one strong cation resin, preferably at least one sulfonic acid resin.

[0129] In other words, an aqueous reaction medium that can be produced by at least one stage (i) and / or by at least one stage (ii) is brought into contact with at least one cation exchange resin, preferably at least one weak cation resin (e.g., a resin having a carboxylic acid active group), and / or at least one strong cation resin, preferably at least one sulfonic acid resin.

[0130] Preferably, the treatment stage (P1) is carried out using at least one cationic resin having a carboxylic acid group and / or at least one sulfonic acid resin, preferably at least one sulfonic acid resin.

[0131] Preferably, the treatment stage (P1) is carried out using at least one cationic resin containing one or more carboxylic acid groups and / or one or more sulfonic acid groups.

[0132] Preferably, the treatment stage (P1) of the reaction medium containing at least one compound of formula (IV) is carried out using at least one sulfonic acid resin.

[0133] Preferably, the cation exchange resin contains one or more sulfonic acid (SO3H) groups and / or one or more sulfonate (-SO3) groups. - ) group, more preferably one or more sulfonate groups (-SO3) - ) group sulfonic acid resin.

[0134] The treatment phase (P1) was carried out at a pH value strictly below the pKa of the compound corresponding to formula (IV').

[0135] When the reaction medium to be processed through at least one treatment stage (P1) contains several different compounds of formula (IV'), the treatment stage (P1) is carried out at a pH value that is strictly lower than the lowest pKa value of the compound of formula (IV').

[0136] When the method comprises several stages (i), the processing stage (P1) can be performed at the end of each stage (i) or at the end of the final stage (i).

[0137] When the method comprises several stages (ii), the processing stage (P1) may be performed at the end of each stage (ii) or at the end of the final stage (ii).

[0138] According to one embodiment, the method includes a single phase (i) and phase (P1) is performed at least once at the end of phase (i).

[0139] According to another embodiment, the method includes a single phase (ii) and phase (P1) is performed at least once at the end of phase (ii).

[0140] According to a preferred embodiment, the method includes a single stage (i) and a single stage (ii), and stage (P1) is performed once or more, preferably once, between stage (i) and stage (ii).

[0141] Preferably, the treatment phase (P1) of the reaction medium produced by the reaction phase (i) is carried out in a pH range extending from 1.5 to 6, preferably from 2 to 4.5, more preferably from 2 to 3.5, and even more preferably from 2.5 to 3.5.

[0142] The processing phase (P1) can be performed once or multiple times, preferably once.

[0143] Separation phase (P2)

[0144] The separation phase (P2) can be performed immediately after phase (P1).

[0145] According to one embodiment, phases (P1) and (P2) are performed sequentially at the end of at least one phase (i).

[0146] According to another embodiment, phases (P1) and (P2) are performed sequentially at the end of at least one phase (ii).

[0147] According to yet another embodiment, at least one stage (P1) is performed at the end of at least one stage (i), and at least one stage (P2) is performed at the end of at least one stage (ii).

[0148] According to another embodiment, the method of the present invention performs at least one stage (P1) at the end of at least one stage (i) and at least one stage (P2) at the end of at least one stage (i) and at the end of at least one stage (ii).

[0149] Preferably, the separation stage (P2) is carried out by distillation or electrodialysis, preferably by vacuum distillation, more preferably by vacuum distillation at a temperature that can vary from 30°C to 80°C, preferably from 30°C to 55°C, and more preferably from 30°C to 50°C.

[0150] Preferably, at least the compound of formula (IV′) is separated from the reaction medium produced by stage (P1) in stage (P2) by distillation or electrodialysis, preferably by vacuum distillation.

[0151] Preferably, at least the compound of formula (IV′) is separated from the reaction medium produced by stage (P1) in stage (P2) by distillation, preferably by vacuum distillation, at a temperature that can vary from 30°C to 80°C, preferably from 30°C to 55°C, and preferably from 30°C to 50°C.

[0152] According to one embodiment, the separation phase (P2) can be performed several times.

[0153] The separation stage (P2), preferably distillation, is carried out several times, depending on the amount of impurity (IV′) desired to be achieved in the composition containing the compound of formula (I).

[0154] In other words, the separation stage (P2), preferably distillation, can advantageously be carried out depending on the grade of the compound of formula (I) to be obtained.

[0155] Preferably, at the end of the separation stage (P2) or the final purification stage (P2), the content of the compound of formula (IV') is less than or equal to 10% by weight relative to the total weight of the dry extract containing the compound of formula (I), preferably less than or equal to 5% by weight, more preferably varying from 1% to 5% by weight, and even more preferably varying from 1% to 2% by weight.

[0156] At the end of the separation stage (P2) or the final separation stage (P2), the content of the compound of formula (IA) relative to the total weight of the dry extract varies from 20% to 70% by weight, preferably from 30% to 60% by weight.

[0157] According to one embodiment, water may be added between the processing stage (P1) or the final processing stage (P1) and at least one separation stage (P2).

[0158] Preferably, at the end of the treatment stage (P1) or the final treatment stage (P1), water may be added and a separation stage (P2) may be performed, preferably by distillation at least once, to separate the compound of at least formula (IV') and water from the reaction medium.

[0159] Preferably, the water addition and separation stage (P2) can be performed several times, which facilitates the separation of the compound of formula (IV') from the reaction medium.

[0160] Additional stages during the purification phase (P)

[0161] Purification (P) may also include one or more additional stages different from stages (P1) and (P2).

[0162] Purification (P) in an aqueous reaction medium containing at least a compound of formula (IV) may include a neutralization phase (P0) of all or part of an excess alkali present in the reaction medium produced by phase (i), simultaneously or sequentially, preferably sequentially, particularly before or after the treatment phase (P1), particularly before the treatment phase (P1).

[0163] Preferably, the at least one purification (P) carried out in an aqueous reaction medium includes: At least one processing stage (P0) is performed to neutralize all or part of the excess alkali present in the reaction medium produced by the at least one stage (i). At least one stage (P1) in which the reaction medium generated by stage (i) is treated with at least one cation exchange resin as defined above, is carried out at a pH value strictly below the pKa of the compound of formula (IV) or below the lowest pKa of the compound of formula (IV) (if several exist). The stage (P2) in which at least one compound of at least formula (IV') is separated from the reaction medium. Optionally, at least one separation stage (P′0) of the compound of formula (III) present in the reaction medium at the end of reaction (i).

[0164] The purification stage (P) may optionally include at least one stage for activating the cation exchange resin to make it acidic.

[0165] The resin activation phase can be carried out before the neutralization phase (P0) and / or before the treatment phase (P1).

[0166] According to one embodiment, the neutralization stage (P0) is carried out with at least one cation exchange resin at a pH value strictly below the pKa of the compound of formula (IV′) or by adding at least one acidifying agent (which is organic or inorganic, preferably inorganic and more preferably selected from the group consisting of inorganic acids as described above) to the reaction medium generated by stage (i).

[0167] Preferably, the neutralization phase (P0) of the excess alkali is carried out with at least one cation exchange resin at a pH value strictly below the pKa of the compound of formula (IV′) or at a value strictly below the lowest pKa of the compound of formula (IV′), preferably in a pH range extending from 1.5 to 6, preferably from 2 to 4.5, more preferably from 2 to 3.5, and even more preferably in a pH range extending from 2.5 to 3.5.

[0168] The cation exchange resin used during the treatment stage (P0) can be the same as or different from that used in the treatment stage (P1), preferably the same.

[0169] In an alternative form, all or part of the neutralization phase (P0) of the at least one alkali can be carried out by adding at least one organic or inorganic, preferably inorganic, acidifying agent to the reaction medium generated by phase (i).

[0170] Preferably, the separation phase (P′0) of the compound of formula (III) is carried out after the neutralization phase (P0).

[0171] More preferably, the separation stage (P′0) of the compound of formula (III) can be carried out by distillation.

[0172] Prior to optionally carrying out at least one reaction stage (ii), the pH of the reaction medium may be altered by adding at least one inorganic acidifier or inorganic or organic base.

[0173] Preferably, the pH of the reaction medium can be altered by adding at least one inorganic acidifying agent, particularly an inorganic acid-type inorganic acidifying agent, such as sulfuric acid, phosphoric acid, sulfonic acid, phosphonic acid, H+, etc. + Hal - An acid, wherein Hal represents a halogen atom selected from the group consisting of chlorine, bromine, and iodine; more preferably, the acidifying agent is hydrochloric acid.

[0174] Reaction phase (ii)

[0175] The preparation method may optionally additionally include at least one reaction stage (ii) in which at least one compound of formula (I) (where X corresponds to the divalent group -C(O)-) (i.e., the compound of formula (IA)) forms at least one compound of formula (I) (where X corresponds to the divalent group -CH(OR)-) (i.e., the compound of formula (IB)).

[0176] According to an advantageous embodiment, the method according to the invention further includes at least one reaction stage (ii) in which a compound of at least formula (IA) forms at least one compound of formula (IB).

[0177] Restoration phase (ii1)

[0178] The reaction stage (ii) is preferably a reduction stage (ii1) carried out in an aqueous medium according to the following synthetic route (B):

[0179] In synthetic pathway (B): SA' and R1 have the same meaning as in equation (I).

[0180] Within the meaning of this invention, a compound of formula (I'B) is a compound of formula (IB), wherein R represents a hydrogen atom.

[0181] In other words, the compound of formula (I′B) is the compound of formula (I), where X corresponds to the divalent group -CH(OR)-, and R represents a hydrogen atom.

[0182] Preferably, the preparation method according to the present invention includes: - At least one reaction stage (i) as described above, - At least one reduction stage (ii1) is carried out in an aqueous medium according to the synthesis pathway (B) as defined above. - At least one purification phase (P) as described above, which is performed before and / or after the reduction phase (ii1).

[0183] The stage of reducing the carbonyl group to produce an alcohol group is carried out by conventional reduction methods known to those skilled in the art. For example, references can be made to work... Advanced Organic Chemistry , J. March, 4th edition, John Wiley & Son, pp. 910-919 (1992). The at least one reduction stage (ii1) can be a reduction, enzymatic reduction or reduction by catalytic hydrogenation in the presence of one or more hydrides, particularly borohydrides (such as NaBH4 or NaBH3CN).

[0184] Preferably, the at least one reduction stage (ii1) is a reduction by catalytic hydrogenation.

[0185] In other words, the at least one reduction stage (ii1) is advantageously hydrogenation carried out in the presence of at least one catalyst and optionally an acidifying agent. Hydrogenation can be, for example, described in the literature (…). Heterocycles [Heterocyclic] The conditions described in M. Hashimoto and M. Takahashi, 77 (1), 227-231 (2009)) were used.

[0186] The catalyst is preferably a metal catalyst, such as ruthenium (Ru), rhodium (Rh), platinum (Pt), iridium (Ir), nickel (Ni) or palladium (Pd), preferably ruthenium (Ru), more preferably a metal catalyst selected from ruthenium (Ru), rhodium (Rh), platinum (Pt) or iridium (Ir), and even more preferably ruthenium (Ru).

[0187] Preferably, the catalyst is supported, and preferably supported with ruthenium, such as ruthenium / carbon (or graphite), ruthenium / alumina, ruthenium / AlSi, ruthenium / zeolite or ruthenium / barium sulfate (BaSO4).

[0188] According to one embodiment, hydrogenation is catalyzed by Pd / carbon (Pd / C) or Ru / carbon (Ru / C).

[0189] Preferably, the catalyst is selected from the group consisting of: ruthenium / carbon (Ru / C), ruthenium / alumina (Ru / Al), ruthenium / AlSi, ruthenium / zeolite, or ruthenium / barium sulfate (BaSO4).

[0190] Preferably, the catalyst is ruthenium (Ru), especially ruthenium / carbon (Ru / C).

[0191] Preferably, the at least one reduction stage (ii1) is a reduction carried out by catalytic hydrogenation in the presence of at least one metal catalyst, especially ruthenium (Ru).

[0192] Preferably, the at least one reduction stage (ii1) is carried out at a hydrogen pressure ranging from 2 to 100 bar, preferably from 3 to 50 bar, more preferably from 4 to 25 bar, even more preferably from 5 to 15 bar, and even more preferably from 6 to 12 bar (such as 10 bar).

[0193] Preferably, the at least one reduction stage (ii1) is carried out at a temperature ranging from 30°C to 150°C, preferably from 40°C to 100°C, and more preferably from 65°C to 100°C.

[0194] Preferably, the at least one reduction stage (ii1) can be carried out over a period of time ranging from 30 minutes to 30 hours, preferably from 45 minutes to 10 hours, and particularly from 1 hour to 7 hours.

[0195] Preferably, the at least one reduction stage (ii1) is a reduction carried out by catalytic hydrogenation in the presence of at least one catalyst, particularly ruthenium, at a hydrogen pressure ranging from 2 to 100 bar and at a temperature ranging from 30°C to 150°C.

[0196] Preferably, the at least one reduction stage (ii1) is a reduction carried out by catalytic hydrogenation in the presence of at least one catalyst, particularly ruthenium, at a hydrogen pressure ranging from 2 to 50 bar and at a temperature ranging from 40°C to 100°C.

[0197] Preferably, the at least one reduction stage (ii1) is a reduction carried out by catalytic hydrogenation in the presence of at least one catalyst, particularly ruthenium, at a hydrogen pressure ranging from 2 to 25 bar and at a temperature ranging from 65°C to 100°C.

[0198] Advantageously, the at least one reduction stage (ii1) is carried out in an aqueous medium: - Under the following conditions: At least one compound of formula (I), wherein X is a divalent group -C(O)-. At least one catalyst, more preferably selected from the group consisting of palladium and ruthenium, particularly ruthenium / carbon, - Under hydrogen pressure ranging from 2 to 50 bar, more preferably from 4 to 12 bar (such as 10 bar); - At a temperature ranging from 40°C to 100°C, preferably from 65°C to 120°C.

[0199] At the end of at least one reduction stage (ii1), the reaction medium can be cooled to a temperature varying from 15°C to 25°C and then purged under nitrogen.

[0200] The reaction medium produced by stage (ii1) is then preferably filtered.

[0201] Preferably, the preparation method according to the present invention comprises the following steps: o At least one reduction phase (ii1) as defined above, Preferably, the reaction medium is subjected to at least one treatment with carbon black before, during, or at the end of the reduction stage (ii1), more preferably before or after the reduction stage (ii1), and particularly before the reduction stage (ii1), wherein the reaction medium is optionally subjected to at least one treatment with carbon black at a temperature ranging from 20°C to 90°C. Optionally, at least one stage involves adding at least one acidifying or alkalizing agent to the reaction medium generated by the reduction stage (ii1). Optionally, at least one compound of formula (IB) is concentrated in the reaction medium produced by the reduction step (ii1) during the concentration phase (ii1). Preferably, the concentration stage (ii1) is carried out by distillation, preferably under reduced pressure. Optionally, at least one purification stage, such as filtration, o Optionally, at least one bactericide or bacterial inhibitor, preferably a bacterial inhibitor, preferably derived from at least one stage of a diol such as propylene glycol, pentanediol, or octanediol (iv), is added. Preferably, the bacterial inhibitor, particularly propylene glycol, is present in a content ranging from 2% to 50% by weight, preferably from 5% to 40% by weight, relative to the total weight of the mixture containing at least the compound of formula (IB) and the bacterial inhibitor. Optionally, at least one purification stage, such as distillation.

[0202] Within the meaning of this invention, the term "biobased" should be understood to mean that compounds described as "biobased" are produced from plant-derived compounds.

[0203] Bonus Phase (ii2)

[0204] The reaction stage (ii) can also be an addition or O-alkoxylation stage (ii2) carried out in an aqueous or non-aqueous medium according to the following synthetic pathway (B1):

[0205] In the synthetic pathway (B1): R corresponds to C1-C 10 Preferably, it is a C1-C4 alkyl group, such as methyl, or a (C1-C4) alkyl carbonyl group, such as acetyl.

[0206] Advantageously, the method according to the invention includes: - At least one stage (i) as defined above, - At least one reaction stage (ii) corresponding to the reduction stage (ii1) as defined above, - At least one reaction stage (ii) corresponding to the addition stage (ii2) as defined above, - At least one purification (P) as defined above, which is carried out at least between the reaction phase (i) and the reduction phase (ii1), and / or at least after the reduction phase (ii1), preferably between the reduction phase (ii1) and the addition phase (ii2), and / or after the addition phase (ii2).

[0207] According to another alternative form of the invention, compound (I"B) is obtained by adding at least one molar equivalent of at least one nucleophilic compound RG to at least one compound of formula (IA), wherein R is as defined above and G represents an electron-deficient atom or group, such as an alkali metal, such as sodium, potassium or lithium, or a magnesium halide, such as MgCl; in particular, the reaction is carried out under an inert atmosphere and in a solvent (preferably a polar aprotic organic solvent, especially an ether solvent, such as diethyl ether or THF), followed by a hydrolysis reaction.

[0208] Packaging of compounds of formula (I)

[0209] At the end of the method according to the invention, the compound of formula (I) (where X corresponds to the divalent group -C(O)- or -CH(OR)-) can be packaged as a dry extract (solvent-free).

[0210] Preferably, at the end of the method according to the invention, the active material of the compound of formula (I) (where X corresponds to the divalent group -C(O)- or -CH(OR)-) in the liquid solution comprises at least 25% by weight relative to the total weight of the solution, preferably in the range of 25% to 80% by weight, more preferably in the range of 25% to 75% by weight, and even more preferably in the range of 30% to 75% by weight.

[0211] Preferably, at the end of the method according to the invention, the active material of the compound of formula (I) (where X corresponds to the divalent group -C(O)- or -CH(OR)-) in a solution of liquid contains at least 20% by weight relative to the total weight of the solution, preferably in the range of 20% to 90% by weight, more preferably in the range of 25% to 80% by weight, and even more preferably in the range of 25% to 75% by weight.

[0212] Preferably, at the end of the method according to the invention, the compound of formula (I) (where X corresponds to the divalent group -C(O)- or -CH(OR)-) in the liquid solution contains active material (I) in an amount of at least 25% by weight relative to the total weight of the solution, more preferably in an amount ranging from 25% to 45% by weight.

[0213] Preferably, at the end of the method according to the invention, the compound of formula (I) (where X corresponds to the group -C(O)- or -CH(OR)-) in the liquid solution contains an active material in an amount of at least 25% by weight relative to the total weight of the solution, more preferably in an amount ranging from 25% to 75% by weight.

[0214] According to one embodiment, a compound of formula (I) (where X corresponds to a divalent group -C(O)- or -CH(OR)-) is packaged in a liquid, and the pH is adjusted to a target value, preferably between 3.5 and 7, by adding at least one alkalizing agent or at least one acidifying agent.

[0215] Chemical structure

[0216] SA' can represent a monosaccharide group in the form of pyranose and / or furanose and of the L and / or D series, α or β anomers, or a polysaccharide group containing up to 6 sugar units, and containing at least one free hydroxyl group and optionally at least one optionally protected amine group.

[0217] Preferably, SA' represents a monosaccharide in the form of pyranose and / or furanose and of the L and / or D series, or a polysaccharide containing up to 6 sugar units and containing at least one free hydroxyl group.

[0218] According to one embodiment, SA' is a monosaccharide group selected from the group consisting of glucose, galactose, mannose, xylose, fucose, arabinose, rhamnose, glucuronic acid, galacturonic acid, iduronic acid, N-acetylglucosamine, and N-acetylgalactosamine, and more particularly, SA is a monosaccharide selected from the group consisting of D-glucose, D-galactose, D-mannose, D-xylose, L-fucose, L-arabinose, L-rhamnose, D-glucuronic acid, D-galacturonic acid, D-iduronic acid, N-acetyl-D-glucosamine, and N-acetyl-D-galactosamine.

[0219] Preferably, SA' is a monosaccharide selected from the group consisting of glucose, xylose, N-acetylgalactosamine and fucose, especially glucose, xylose and fucose, and more particularly xylose.

[0220] More preferably, SA' is a monosaccharide group selected from the group consisting of D-glucose, D-xylose, N-acetyl-D-galactosamine and L-fucose, especially D-glucose, D-xylose and L-fucose, and even more particularly D-xylose.

[0221] According to one embodiment, SA' is a polysaccharide group comprising up to 6 sucrose units and selected from the group consisting of: D-maltose, D-lactose, D-cellobiose, D-maltotriose, a disaccharide consisting of a uronic acid selected from D-iduronic acid or D-glucuronic acid and a hexosamine selected from D-galactosamine, D-glucosamine, N-acetyl-D-galactosamine or N-acetyl-D-glucosamine, an oligosaccharide containing at least one xylose, advantageously selected from xylobiose, methyl β-xylobiose, xylotriose, xylotetraose, xypentose and xyhexaose, and preferably xylobiose (which consists of two xylose molecules linked via a β-1-4 bond).

[0222] Preferably, SA' represents a monosaccharide.

[0223] Preferably, SA' represents a monosaccharide group selected from the group consisting of: glucose, especially D-glucose; xylose, especially D-xylose; fucose, especially L-fucose; arabinose, especially L-arabinose; rhamnose, especially L-rhamnose; glucuronic acid, especially D-glucuronic acid; galacturonic acid, especially D-galacturonic acid; iduronic acid, especially D-iduronic acid; N-acetylglucosamine, especially N-acetyl-D-glucosamine; and N-acetylgalactosamine, especially N-acetyl-D-galactosamine, and preferably SA' is selected from D-glucose, D-xylose, L-fucose, L-arabinose, L-rhamnose, D-glucuronic acid, D-galacturonic acid, or D-iduronic acid.

[0224] Preferably, SA' represents a monosaccharide group selected from the group consisting of glucose, xylose, N-acetylgalactosamine and fucose; more preferably, SA' is selected from the group consisting of glucose, xylose and fucose.

[0225] Preferably, SA' represents a monosaccharide group selected from the group consisting of D-glucose, D-xylose, N-acetyl-D-galactosamine and L-fucose; more preferably, SA' is selected from the group consisting of D-glucose, D-xylose and L-fucose.

[0226] More preferably, SA' represents a xylose group and even more preferably D-xylose.

[0227] As indicated above, R1 represents saturated or unsaturated, straight-chain or branched, cyclic or acyclic C1-C. 10 Preferably C1-C6, more preferably C1-C4, especially C1 hydrocarbon chains.

[0228] According to one embodiment, R1 represents a saturated or unsaturated, straight or branched, cyclic or acyclic, preferably acyclic C1-C6, more preferably C1-C4, particularly C1 hydrocarbon chain.

[0229] According to one embodiment, R1 represents a saturated or unsaturated, straight or branched, cyclic (such as cyclohexyl or cyclopentyl), or acyclic C1-C6, more preferably C1-C4, particularly C1 hydrocarbon chain.

[0230] Preferably, R1 represents a saturated or unsaturated, straight-chain or branched, preferably straight-chain, acyclic C1-C. 10 Preferably C1-C6, more preferably C1-C4, especially C1 hydrocarbon chains.

[0231] Preferably, R1 represents a saturated or unsaturated, straight-chain, acyclic C1-C... 10 Preferably C1-C6, more preferably C1-C4, especially C1 hydrocarbon chains.

[0232] Preferably, R1 represents a saturated or unsaturated, straight-chain, acyclic C1-C4, especially C1 alkyl chain.

[0233] Preferably, X represents a divalent group -C(O)- or -CH(OH)-.

[0234] Advantageously, in equation (I): -X represents a divalent group -C(O)- or -CH(OH)-. - SA' represents a monosaccharide group selected from the group consisting of: D-glucose, D-galactose, D-mannose, D-xylose, L-fucose, L-arabinose, L-rhamnose, D-glucuronic acid, D-galacturonic acid, D-iduronic acid, N-acetyl-D-glucosamine and N-acetyl-D-galactosamine, preferably selected from D-glucose, D-galactose, D-mannose, D-xylose, L-fucose, L-arabinose, L-rhamnose, D-glucuronic acid, D-galacturonic acid or D-iduronic acid, more preferably selected from D-glucose, D-xylose or L-fucose; - R1 represents a saturated or unsaturated, straight-chain, acyclic C1-C. 10 Preferably, it consists of C1-C6, more preferably C1-C4 hydrocarbon chains, especially methyl groups.

[0235] According to one embodiment, in formula (III), R1 and R2 are the same and represent saturated or unsaturated, straight or branched, cyclic or acyclic, preferably acyclic C1-C6, more preferably C1-C4, particularly C1 hydrocarbon chains.

[0236] Preferably, in formula (III), R1 and R2 are the same and represent saturated or unsaturated, straight or branched, acyclic C1-C6, more preferably C1-C4, especially C1 hydrocarbon chains.

[0237] Preferably, in formula (III), R1 and R2 are the same and represent saturated or unsaturated, straight-chain, acyclic C1-C4, especially C1 hydrocarbon chains.

[0238] According to one embodiment, in formula (IV), R2 represents a saturated or unsaturated, straight or branched, cyclic or acyclic, preferably acyclic C1-C6, more preferably C1-C4, particularly C1 hydrocarbon chain.

[0239] Preferably, in formula (IV), R2 represents a saturated or unsaturated, straight or branched, acyclic C1-C6, more preferably C1-C4, particularly C1 hydrocarbon chain.

[0240] Preferably, in formula (IV), R2 represents a saturated or unsaturated, straight-chain, acyclic C1-C4, especially C1 hydrocarbon chain.

[0241] Preferably, in formulas (I), (III), and (IV), R1 and R2 are identical and represent saturated or unsaturated, linear, acyclic C1-C1 bonds. 10 Preferably, C1-C4, especially C1 hydrocarbon chains.

[0242] According to one embodiment, D can be an organic cation, preferably selected from the group consisting of ammonium, phosphonium, imidazolium, pyrazolium, piperidinium, and piperazineium ions.

[0243] According to one embodiment, D is an inorganic cation selected from the group consisting of alkali metal cations and alkaline earth metal cations.

[0244] Advantageously, D is a cation selected from the group consisting of alkali metal cations, alkaline earth metal cations, and ammonium ions (NH4+). + (in particular, alkali metal cations and alkaline earth metal cations).

[0245] Preferably, D is a cation selected from the group consisting of: calcium ions (Ca ions) 2+ ), magnesium ions (Mg 2+ Sodium ions (Na) + ) and potassium ions (K + (In particular, calcium and sodium ions, especially sodium ions).

[0246] Advantageously, SA' corresponds to the following formula (II'):

[0247] In equation (II'), the exponent n is equal to 0 or 1, preferably equal to 1, and the exponent p is an integer ranging from 1 to 4; preferably, the exponent p is equal to 3.

[0248] Preferably, in equation (II'), n equals 1 and p is an integer ranging from 1 to 4; preferably, the exponent p equals 3.

[0249] More preferably, in equation (II′), n equals 1 and p equals 3.

[0250] The method for preparing at least one compound of formula (I) is preferably a method for preparing at least one compound of formula (I'):

[0251] In equation (I'): - n is equal to 0 or 1, preferably equal to 1. - p is an integer ranging from 1 to 4; preferably, the exponent p equals 3. - R1 exhibits the same meaning as in equation (I), preferably representing a linear, preferably acyclic C1-C 10 Preferably C1-C6, more preferably C1-C4, especially C1 hydrocarbon chains; - X represents a divalent group -C(O)- or -CH(OR)-. - R represents a hydrogen atom, C1-C 10 Preferably, it is a C1-C4 alkyl group, such as methyl, or a (C1-C4) alkyl carbonyl group, such as acetyl; preferably, R represents a hydrogen atom. And also one of its optical isomers, geometric isomers, and / or its solvates—such as hydrates— The method includes: - Carry out at least one reaction stage (i) according to the following synthetic scheme (A'):

[0252] In the synthetic pathway (A'): on equals 0 or 1, preferably equal to 1. op is an integer ranging from 1 to 4; preferably, the exponent p equals 3. R1 and R2 are the same or different, preferably the same, wherein R2 has the same meaning as R1 in equation (I'). o D + It is an organic or inorganic cation, preferably an inorganic cation, and more preferably a free alkali metal cation, alkaline earth metal cation, and ammonium cation (NH4). + The group composed of alkali metal cations and alkaline earth metal cations is even better selected. The reaction phase (i) is carried out in an aqueous medium in the presence of the following: o At least one compound of formula (II'), o Preferably, at least one compound of formula (III) is present in an equimolar amount or in excess, preferably in excess, relative to the compound of formula (II'). Preferably, the molar ratio of the compound of formula (III) to the compound of formula (II') is greater than or equal to 1, preferably between 1 and 5, more preferably between 1 and 4, even more particularly between 1 and 3, even better between 1 and 2, and particularly ranging from 1 to 1.5; according to a specific embodiment, the molar ratio of the compound of formula (III) to the compound of formula (II') is greater than 1. o At least one alkali agent in an equimolar amount or in excess, preferably in excess, relative to the compound of formula (II'), Preferably, the molar ratio of the alkali agent to the compound of formula (II') is greater than or equal to 1, preferably between 1 and 5, more preferably between 1 and 4, even more particularly between 1 and 3, and even more preferably between 1 and 2; according to a specific embodiment, the molar ratio of the alkali agent to the compound of formula (II') is greater than 1. The alkali agent is preferably inorganic, more preferably selected from the group consisting of alkali metal hydroxides and alkaline earth metal hydroxides, alkali metal carbonates (hydrogenates) and alkaline earth metal carbonates (hydrogenates), and mixtures thereof; particularly alkali metal hydroxides and alkaline earth metal hydroxides, such as sodium hydroxide. To result in the formation of at least one compound of formula (I'A1) and at least one compound of formula (IV); - Optionally, at least one reaction stage (ii) of the compound of formula (I'A1) is performed to produce at least one compound corresponding to formula (I'B1):

[0253] In equation (I'B1), the exponents n and p, as well as R1, have the same meaning as in equation (I); Preferably, the reaction stage (ii) is the reduction stage (ii1) as defined above. - At least one purification (P) of a reaction medium comprising at least a compound of formula (IV) in an aqueous medium, comprising, in sequence: At least one processing stage (P1) is carried out using at least one cation exchange resin according to the following scheme in order to convert at least the compound of formula (IV) into the compound of formula (IV'):

[0254] The treatment phase (P1) is carried out at a pH strictly below the pKa of the compound of formula (IV') or below the lowest pKa of the compound of formula (IV') (if several exist). - A stage (P2) in which at least one compound of formula (IV') is separated from the reaction medium.

[0255] The reaction phase (i) and purification phase (P) are as defined above.

[0256] Preferably, purification (P) is carried out after reaction stage (i).

[0257] Preferably, purification (P) is performed at least between reaction stage (i) and at least one reaction stage (ii), and / or at least after at least one reaction stage (ii), for example, after one and / or two reaction stages (ii).

[0258] Preferably, reaction stage (ii) is a reduction stage (ii1) carried out in an aqueous medium according to the following synthetic route (B1):

[0259] In the synthetic pathway (B1): - The exponents p and R1 have the same meaning as in equation (I).

[0260] Preferably, the reduction stage (ii1) is a reduction by catalytic hydrogenation as defined above.

[0261] Within the meaning of this invention, a compound of formula (I'A1) is a compound of formula (I'), wherein X corresponds to a divalent group -C(O)-.

[0262] Within the meaning of this invention, a compound of formula (I'B1) is a compound of formula (I'), wherein X corresponds to the divalent group -CH(OH)-.

[0263] Preferably, purification (P) is carried out at least between the reaction phase (i) as described above and the reduction step (ii1) as described above.

[0264] More preferably, the method for preparing at least one compound of formula (I) is a method for preparing at least one compound of formula (I''):

[0265] And also one of its optical isomers, geometric isomers, and / or its solvates—such as hydrates— The method includes: - Carry out at least one reaction stage (i) according to the following synthetic scheme (A''):

[0266] In the synthetic pathway (A''): o D + It is a cation selected from the following groups: alkali metal cations, alkaline earth metal cations, and ammonium ions (NH4+). + ); The reaction phase (i) is carried out in an aqueous medium in the presence of the following: o Preferably, at least one compound of formula (III') is present in an equimolar amount or in excess relative to the compound of formula (II''). Preferably, the molar ratio of the compound of formula (III) to the compound of formula (II'') is greater than or equal to 1, preferably between 1 and 5, more preferably between 1 and 4, even more particularly between 1 and 3, even better between 1 and 2, and particularly ranging from 1 to 1.5; according to a specific embodiment, the molar ratio of the compound of formula (III) to the compound of formula (II'') is greater than 1. o At least one alkali agent in an equimolar amount or in excess, preferably in excess, relative to the compound of formula (II'') Preferably, the molar ratio of the alkali agent / compound of formula (II'') is greater than or equal to 1, preferably between 1 and 5, more preferably between 1 and 4, even more particularly between 1 and 3, and even better between 1 and 2; according to a specific embodiment, the molar ratio of the alkali agent / compound of formula (II'') is greater than 1. The alkali agent is preferably inorganic, more preferably selected from the group consisting of alkali metal hydroxides and alkaline earth metal hydroxides, especially sodium hydroxide. To result in the formation of at least one compound of formula (I''A) and at least one compound of formula (IV''); - Optionally, at least one reaction stage (ii) of the compound of formula (I''A) is performed to produce at least one compound corresponding to the following formula (I''B): Preferably, the reaction stage (ii) is the reduction stage (ii1) as defined above. - At least one purification (P) of a reaction medium comprising at least a compound of formula (IV'') carried out in an aqueous medium, comprising in sequence: At least one processing stage (P1) is carried out with at least one cation exchange resin according to the following scheme in order to convert at least the compound of formula (IV'') into the compound of formula (IV'''):

[0267] The treatment phase (P1) is carried out at a pH strictly below the pKa of the compound of formula (IV''') or below the lowest pKa of the compound of formula (IV''') (if several exist). The stage in which at least one compound of formula (IV''') is separated from the reaction medium.

[0268] The reaction phase (i) and purification phase (P) are as defined above.

[0269] Preferably, purification (P) is performed at least between reaction stage (i) and at least one reaction stage (ii), and / or at least after at least one reaction stage (ii), for example, after one and / or two reaction stages (ii).

[0270] Within the meaning of this invention, a compound of formula (I''A) is a compound of formula (I''), wherein X corresponds to a divalent group -C(O)-.

[0271] Within the meaning of this invention, compounds of formula (I''B) are compounds of formula (I''), wherein X corresponds to the divalent group -CH(OH)-.

[0272] Preferably, reaction stage (ii) is a reduction stage (ii1) carried out in an aqueous medium according to the following synthetic route (B''):

[0273] Preferably, the reduction stage (ii1) is a reduction by catalytic hydrogenation as defined above.

[0274] Preferably, purification (P) is performed at least between reaction stage (i) and at least one reduction stage (ii1), and / or at least after at least one reduction stage (ii1), for example, after one and / or two reaction stages (ii).

[0275] Preferably, purification (P) is carried out at least between the reaction phase (i) and the reduction phase (ii1).

[0276] The method for preparing at least one compound of formula (I') or (I") may also include additional stages as described for the method for preparing at least one compound of formula (I).

[0277] Purification methods

[0278] The present invention also relates to a method for purifying at least one aqueous medium comprising at least one compound corresponding to formula (I) as defined above and at least one compound as defined above, comprising: At least one processing stage (P1) is carried out using at least one cation exchange resin according to the following scheme in order to convert at least the compound of formula (IV) into the compound of formula (IV'):

[0279] The treatment phase (P1) is carried out at a pH strictly below the pKa of the compound of formula (IV') or below the lowest pKa of the compound of formula (IV') (if several exist), and The stage (P2) in which at least one compound of formula (IV') is separated from the reaction medium.

[0280] The processing phase (P1) and the separation phase (P2) are as defined above.

[0281] Within the meaning of this invention, the term "aqueous medium" should be understood to mean any aqueous medium that does not contain any water-miscible organic solvents as defined above, and preferably an aqueous medium that does not contain any organic solvents.

[0282] Therefore, the purification method is carried out in an aqueous medium containing at least one compound of formula (IV) that does not contain any water-miscible organic solvents (i.e., an aqueous reaction medium that does not contain water-miscible organic solvents, preferably an aqueous reaction medium that does not contain organic solvents).

[0283] In other words, water-miscible organic solvents are not used in the treatment stage (P1) and the separation stage (P2).

[0284] More specifically, the treatment stage (P1) and separation stage (P2) do not use organic solvents that are miscible or immiscible with water. Detailed Implementation

[0285] The present invention will be described in more detail in the following non-limiting examples.

[0286] Example: Example 1 – Preparation of C-β-D-xylanopyranoside-2-hydroxypropane (47 wt%)

[0287] Stage 1: Preparation of compounds of formula (I'')

[0288] At 20°C, water (1.04 kg) is added to the reactor. Heating is carried out to 50°C, then D-xylose (700 g) is added and stirred until the medium is homogeneous. The mixture is cooled to 15°C and acetylacetone (555 g) is added. A 50% sodium hydroxide solution (540 g) is added at a temperature below 45°C. The mixture is then heated from 30°C to 50°C for a period of 30 minutes to 4 hours, then optionally cooled to 20°C and passed through a strong sulfonic acid ion exchange resin until the pH is between 2.5 and 3.5.

[0289] This was followed by several cycles of adding water and distilling water until an acetic acid content of less than 10,000 ppm, and in fact even less than or equal to 6,000 ppm, and a dry extract of 30% to 60% were obtained. The pH was then adjusted to 6.0-7.0.

[0290] The product was separated in solution, with a yield of 90%-95%.

[0291] Stage 2: Catalytic hydrogenation to obtain a compound of formula (I'1)

[0292] A compound of formula (I') in an aqueous solution with an appropriate acetic acid content (2.08 kg) is introduced into a hydrogenator with ruthenium / carbon (catalytic amount). The mixture is purged with nitrogen at least once, and then with hydrogen. The mixture can be heated to a temperature greater than 25°C, and then hydrogen is introduced at a pressure up to about 10 bar.

[0293] The mixture is heated to a temperature of less than or equal to 100°C at a pressure ranging from 8 to 12 bar for a duration ranging from 2 to 7 hours.

[0294] The hydrogenation reaction continues until the hydrogen is completely consumed.

[0295] The reaction medium can be restored to ambient temperature (20°C) and then optionally purged with an inert gas (nitrogen). The catalyst is then filtered out, and the filtrate is then optionally contacted with carbon black. The solution is concentrated until a dry extract of 40% to 80% is obtained.

[0296] Adjust the pH of the filtrate to an acidic pH (e.g., between 4 and 6).

[0297] A diol derivative (such as propylene glycol) can be added to the above solution as a solvent to obtain a content of 20% to 90% of the compound of formula (I).

[0298] The product was separated in solution with good yield (between 90% and 95%) and acetic acid content less than 20,000 ppm.

Claims

1. A process for the preparation of at least one compound of the following formula (I): (I) in formula (I): - SA' represents a monosaccharide radical or a polysaccharide radical comprising up to 20 saccharide units, in particular up to 6 saccharide units, in pyranose and / or furanose form and of the L and / or D series, said monosaccharide radical or polysaccharide radical having at least one substituted free hydroxyl group, and optionally at least one optionally protected amine group, - the bond between SA' and CH2-X is a bond of C-anomeric nature, - X represents a divalent radical -CH(OR)-, - R represents a hydrogen atom, a C1-C4 alkyl group such as methyl, or a (C1-C4)alkylcarbonyl group such as acetyl, preferably a hydrogen atom, 10 , preferably a C1-C4 alkyl group such as methyl, or a (C1-C4)alkylcarbonyl group such as acetyl, preferably a hydrogen atom, - R1 represents a saturated or unsaturated, linear or branched, cyclic or acyclic, preferably acyclic, C1-C 10 , preferably C1-C4, more preferably saturated, hydrocarbon chain, - R1 represents a saturated or unsaturated, linear or branched, cyclic or acyclic, preferably acyclic, C1-C 10 , preferably C1-C4, more preferably saturated, hydrocarbon chain, - R1 represents a saturated or unsaturated, linear or branched, cyclic or acyclic, preferably acyclic, C1-C 10 and also one of its optical isomers, geometric isomers, and / or solvates thereof such as hydrates, said process comprising: - at least one reaction stage (i) according to the following synthesis scheme (A): In the synthesis route ( A ) :​ R1and R2are identical or different, wherein R2has the same meaning as R1in said formula (I), SA' has the same meaning as in said formula (I), D + is an organic or inorganic cation resulting from a base agent; preferably, D + is an inorganic cation; said reaction stage (i) being carried out in aqueous medium in the presence of: at least one compound of formula (II), at least one compound of formula (III), and at least one base agent in equimolar amounts or in excess, preferably in excess, relative to the compound of formula (II), to result in the formation of at least one compound of formula (IA) and at least one compound of formula (IV), - at least said compound of formula (IA) in at least one reaction stage (ii) in preferably aqueous medium to result in the formation of at least one compound corresponding to the following formula (IB): in formula (IB), SA', R1 and R have the same meaning as in said formula (I); said reaction stage (ii) being at least one reduction stage (ii1) by catalytic hydrogenation carried out in the presence of at least one metal catalyst, - at least one purification (P) of the reaction medium comprising at least said compound of formula (IV) carried out in aqueous medium, comprising: o at least one treatment stage (P1) according to the following scheme with at least one cationic ion exchange resin in order to transform at least said compound of formula (IV) into a compound of formula (IV'): said treatment stage (P1) being carried out at a pH strictly below the pKa of said compound of formula (IV') or below the lowest pKa of said compound of formula (IV') if several exist, o at least one stage (P2) of separation of at least said compound of formula (IV') from the reaction medium. said reaction stage (i) being carried out in aqueous medium in the presence of:

2. The method of claim 1, wherein, o at least one compound of formula (II), o at least one compound of formula (III), o at least one inorganic base agent, preferably selected from the group consisting of alkali metal hydroxides and alkaline earth metal hydroxides, alkali metal carbonates and alkaline earth metal carbonates, and mixtures thereof; in particular alkali metal hydroxides and alkaline earth metal hydroxides such as sodium hydroxide, Preferably, the molar ratio of the compound of formula (III) / compound of formula (II) is greater than or equal to 1, preferably between 1 and 5, more preferably between 1 and 4, still more particularly between 1 and 3, still better between 1 and 2, in particular ranging from 1 to 1.5; in particular, the molar ratio of the compound of formula (III) / compound of formula (II) is greater than 1. o preferably, said reaction stage (i) is carried out: as the base agent in equimolar amounts or in excess, preferably the molar ratio of the base agent / compound of formula (II) is greater than or equal to 1, preferably between 1 and 5, more preferably between 1 and 4, still more particularly between 1 and 3, still better between 1 and 2, o preferably, the duration of the reaction varies as follows: at a temperature ranging from 20°C to 80°C, preferably at a temperature ranging from 20°C to 70°C, more preferentially at a temperature ranging from 30°C to 70°C, better still from 30°C to 60°C, even better still at a temperature ranging from 35°C to 45°C; o preferably, the duration of the reaction varies as follows: from 10 minutes to 10 hours, preferably from 20 minutes to 5 hours, more preferably from 30 minutes to 4 hours, still more preferably from 45 minutes to 3 hours.

3. The method according to claim 1 or 2, characterized in that, Said purification (P) can be carried out at least once between the reaction stage (i) and at least one reaction stage (ii) and / or at least once after at least one reaction stage (ii); preferably, said purification (P) is carried out at least once at the end of the reaction stage (i).

4. The method according to any of the preceding claims, characterized in that, Said purification (P) is carried out in an aqueous reaction medium comprising at least said compound of formula (IV) and being free of any water-miscible organic solvent, preferably free of any organic solvent chosen from the group consisting of dichloromethane, diethyl ether, ethanol, methanol, isopropanol, butanol, isobutanol, tert-butanol, toluene, isopropanol and mixtures thereof, more preferably free of any organic solvent.

5. The method according to any of the preceding claims, characterized in that, Said treatment stage (P1) is carried out with at least one cationic resin having carboxylic acid groups and / or at least one sulfonic acid resin, preferably at least one sulfonic acid resin.

6. The method according to any of the preceding claims, characterized in that, Said treatment stage (P1) is carried out at a pH ranging from 1.5 to 6, preferably ranging from 2 to 4.5, more preferably ranging from 2 to 3.5, better still in a pH range extending from 2.5 to 3.

5.

7. The method according to any of the preceding claims, characterized in that, Said separation stage (P2) is carried out by distillation or electrodialysis, preferably by vacuum distillation, more preferably by vacuum distillation at a temperature varying from 30°C to 80°C, preferably from 30°C to 55°C, preferably from 30°C to 50°C.

8. The method according to any of the preceding claims, characterized in that, At the end of said separation stage (P2), the content of compound of formula (IV’) is less than or equal to 10% by weight, preferably less than or equal to 5% by weight, more preferably varying from 1% to 5% by weight, better still varying from 1% to 2% by weight, relative to the total weight of dry extract containing the compound of formula (I).

9. The method according to any of the preceding claims, characterized in that, Said purification (P) comprises, simultaneously or sequentially, preferably sequentially, in particular before or after the treatment stage (P1), more preferably before the treatment stage (P1), at least one neutralization stage (P0) of all or part of the excess base agent present in the reaction medium resulting from stage (i).

10. The method according to any of the preceding claims, characterized in that, Said at least one purification stage (P) carried out in an aqueous reaction medium comprises: o at least one treatment stage (P0) to neutralize all or part of the excess base agent present in the reaction medium resulting from said at least one stage (i), o at least one stage (P1) of treatment of the reaction medium resulting from stage (i) with at least one cationic ion exchange resin, carried out at a pH strictly lower than the pKa of the compound of formula (IV’) or lower than the lowest pKa of the compound of formula (IV’), o at least one stage (P2) of separation of at least the compound of formula (IV’) from the reaction medium, o at least one separation stage (P’0) of the compound of formula (III) present in the reaction medium at the end of the reaction (i).

11. The method according to claim 9 or 10, characterized in that, The neutralization stage (P0) can be carried out at a pH strictly lower than the pKa of the compound of formula (IV') with at least one cationic ion exchange resin, or by adding at least one organic or inorganic, preferably inorganic, acidifying agent to the reaction medium resulting from stage (i).

12. The method according to any of the preceding claims, characterized in that, The reaction stage (ii) is a reduction stage (ii1) in an aqueous medium according to the following synthesis pathway (B): In synthesis pathway (B): SA' and R1have the same meaning as in said formula (I).

13. The method of claim 12, wherein, The reaction stage (ii) is at least one reduction stage (ii1) by catalytic hydrogenation in the presence of at least one metal catalyst chosen from ruthenium (Ru), nickel (Ni) or palladium (Pd).

14. The method according to any of the preceding claims, characterized in that, The solution of the compound of formula (I) in a liquid, in which X corresponds to the divalent radical -CH(OR)-, comprises an active material (I) content of at least 25% by weight relative to the total weight of the solution, preferably with a content ranging from 25% to 80% by weight, more preferentially ranging from 25% to 75% by weight, more preferentially ranging from 30% to 75% by weight.

15. The method according to any of the preceding claims, characterized in that, It comprises at least one stage (iv) of addition of at least one bactericide or bacteriostatic agent, preferably a bacteriostatic agent, preferably derived from a glycol such as propylene glycol, pentylene glycol or octylene glycol.

16. The method according to any of the preceding claims, characterized in that, SA' represents a monosaccharide radical chosen from the group consisting of glucose, in particular D-glucose, xylose, in particular D-xylose, fucose, in particular L-fucose, arabinose, in particular L-arabinose, rhamnose, in particular L-rhamnose, glucuronic acid, in particular D-glucuronic acid, galacturonic acid, in particular D-galacturonic acid, iduronic acid, in particular D-iduronic acid, N-acetylglucosamine, in particular N-acetyl-D-glucosamine, and N-acetylgalactosamine, in particular N-acetyl-D-galactosamine, and preferably SA' is chosen from D-glucose, D-xylose, L-fucose, L-arabinose, L-rhamnose, D-glucuronic acid, D-galacturonic acid or D-iduronic acid.

17. The method according to any of the preceding claims, characterized in that, R1represents a saturated or unsaturated, straight-chain or branched, cyclic or acyclic C1-C 10 , preferably C1-C6, more preferably C1-C4, in particular C1hydrocarbon chain.

18. The method according to any of the preceding claims, characterized in that, R1 and R2 are identical and represent a saturated or unsaturated, straight-chain, acyclic C1-C6, more preferentially C1-C4, in particular C1 hydrocarbon chain.

19. The method according to any of the preceding claims, characterized in that, X represents the divalent radical -CH(OH)-.

20. The method according to any of the preceding claims, characterized in that, D + is a cation selected from the group consisting of alkali metal cations, alkaline earth metal cations and ammonium ions (NH4 + ), preferably alkali metal cations and alkaline earth metal cations, in particular selected from the group consisting of calcium ions (Ca 2+ ), magnesium ions (Mg 2+ ), sodium ions (Na + ) and potassium ions (K + ).

21. A process for purifying at least one aqueous medium comprising at least one compound of formula (I) as defined according to any one of Claims 1, 16, 17 and 19 and at least one compound of formula (IV) as defined according to Claim 1 or 20, said process comprising in succession: - at least one treatment stage (P1) carried out according to the following scheme with at least one cationic ion exchange resin in order to transform at least the compound of formula (IV) into a compound of formula (IV'): said treatment stage (PI) is carried out at a pH strictly lower than the pKa of the compound of formula (IV') or lower than the lowest pKa of the compound of formula (IV') if several exist, and - at least one stage (P2) of separation of at least the compound of formula (IV') from the reaction medium, - at least one reduction stage (ill) by catalytic hydrogenation carried out in the presence of at least one metal catalyst.

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