A method for the preparation of blood group H1 and H3 receptors

Abstract

This invention provides a method for preparing blood type H1 and H3 receptors. Specifically, the method includes: (1) in a solvent, compound 5 undergoes a first glycosylation reaction with compound III to obtain a first product; (2) removing the photosensitizing group from the first product by light irradiation. o NBC, to obtain the second product; (3) the second product undergoes a second glycosylation reaction with compound 7 to obtain compound 8; or, (1') compound 9 undergoes a first glycosylation reaction with compound of formula III to obtain the fourth product; (2') the photosensitive protecting group in the fourth product is removed by light irradiation. o NBC yields the fifth product; (3') the fifth product undergoes a second glycosylation reaction with compound 7 to yield compound 11. This method employs a photosensitive one-pot strategy, with mild reaction conditions, shortened purification steps, and is simple and efficient. This method can be used to obtain large quantities of blood type H1 and H3 antigens and their receptors.

Description

Technical Field

[0001] This invention belongs to the field of medicinal chemistry, and specifically relates to a method for preparing blood type H1 and H3 antigens and their receptors using a photosensitive one-pot method. Background Technology

[0002] The chemical structural formulas of blood group H1 antigen 1, H3 antigen 2, H1 receptor 3, and H3 receptor 4 are as follows:

[0003] Norovirus has become a major pathogen causing acute gastroenteritis worldwide. The most effective strategy for preventing infection is vaccination. However, research is limited due to the high polymorphism of the virus strains, the extreme difficulty of in vitro culture, and the lack of effective animal models. To date, no approved preventative vaccine has been developed. The infection mechanism of norovirus is closely related to the binding ability of human tissue blood group antigens (HGBAs). There are significant differences in susceptibility to norovirus among individuals with different blood types, with individuals of blood type H having the highest risk of infection.

[0004] To further investigate the specific binding mechanism of norovirus to HGBAs receptors on the surface of host cells, a sufficient quantity of blood group H receptors is needed for systematic mechanistic exploration, which has become crucial for the development of anti-norovirus drugs. Therefore, there is an urgent need in this field for a method that can rapidly synthesize large quantities of blood group H receptors. Summary of the Invention

[0005] The purpose of this invention is to solve the problem of obtaining large quantities of blood type H1 and H3 receptors, and to provide a simple, high-yield, and low-cost chemical synthesis route for blood type H1 receptor (compound 3) and blood type H3 receptor (compound 4).

[0006] The first aspect of the present invention provides a method for preparing compound 8 or 11, the method comprising: (1) In a solvent, compound 5 undergoes a first glycosylation reaction with compound III to obtain the first product; (2) The photosensitive protecting group in the first product is removed by light irradiation. o NBC, to obtain the second product; (3) the second product undergoes a second glycosylation reaction with compound 7 to obtain compound 8; or, (1') Compound 9 undergoes a first glycosylation reaction with compound of formula III to give the fourth product; (2') the photoprotective group in the fourth product is removed by light irradiation. o NBC, to obtain the fifth product; (3') the fifth product undergoes a second glycosylation reaction with compound 7 to obtain compound 11; ; ; In Equation III, LG is selected from: , , and ; In Equation III o NBC is o-nitrobenzyloxycarbonyl ( ); The TCA in compound 5 is trichloroacetyl (TCA). ); The first glycosylation reaction and / or the second glycosylation reaction may optionally include an activating agent for activating compound III and / or compound 7 to participate in the reaction.

[0007] A second aspect of the present invention provides a method for preparing compound 1, the method comprising the steps of: (a) In a solvent, compound 8 is reacted with a base to yield an intermediate; (b) In a solvent, the intermediate reacts with hydrogen under the action of a catalyst to give compound 1; The method further includes preparing compound 8 using the method described in the first aspect of the present invention; .

[0008] A third aspect of the present invention provides a method for preparing compound 2, the method comprising the steps of: (a') In the solvent, compound 11 reduces the azide group to an amino group under the action of a reducing agent to obtain intermediate A; (b') In the solvent, intermediate A reacts with an amino protecting agent to protect the amino group and obtain intermediate B; (c') In the solvent, intermediate B is reacted with a base to yield intermediate C; (d') In the solvent, under the action of a catalyst, intermediate C reacts with hydrogen to give compound 2; The method further includes preparing compound 11 using the method described in the first aspect of the present invention; .

[0009] A fourth aspect of the present invention provides a method for preparing compound 3 or 4, the method comprising the steps of: (A) In a solvent, in the presence of a base, compound 13 reacts with compounds 1 and 15; (B) ethanolamine is then added to further react, yielding compound 3; the method further includes preparing compound 1 using the method described in the second aspect of the invention; or, (A') In a solvent, in the presence of a base, compound 13 reacts with compound 2 and compound 15; (B') ethanolamine is then added to react and give compound 4; the method further includes preparing compound 2 using the method described in the third aspect of the present invention; ; .

[0010] The fifth aspect of this invention provides the use of compounds of formula I or formula II in the preparation of carbohydrate compounds; (1) Compound of Formula I:

[0011] (I)

[0012] In Formula I: Each hydroxyl group may be optionally replaced by a first protecting group; one, two, or three H atoms in NH and NH2 may be optionally replaced by a second protecting group; Each of the first protecting groups is independently selected from: benzyl, p-methoxybenzyl, 3,4-dimethoxybenzyl, triphenylmethyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, triisopropylsilyl, acetyl, benzoyl, neopentanoyl, chloroacetyl, bromoacetyl, benzylene, isopropylene, allyl, allyloxycarbonyl, propargyl, nitroveratroloxy, 9-fluorenemethoxycarbonyl, azide, phenylthio, and methylthio; Each of the second protecting groups is independently selected from: benzyl, tert-butoxycarbonyl, triphenylmethyl, 9-fluorenyloxycarbonyl, acetyl, benzyloxycarbonyl, allyloxycarbonyl, phthaloyl, trifluoroacetyl, and p-toluenesulfonyl; Alternatively, two hydroxyl groups on adjacent carbons of the sugar ring are replaced by two first protecting groups, which together form a ketal or acetal structure. (2) Compound of Formula II:

[0013] (II)

[0014] In Formula II: Each hydroxyl group may be optionally replaced by a third protecting group; one, two or three H atoms in NH and NH2 may be optionally replaced by a fourth protecting group; Each of the third protecting groups is independently selected from: benzyl, p-methoxybenzyl, 3,4-dimethoxybenzyl, triphenylmethyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, triisopropylsilyl, acetyl, benzoyl, neopentanoyl, chloroacetyl, bromoacetyl, benzylene, isopropylene, allyl, allyloxycarbonyl, propargyl, nitroveratroloxy, 9-fluorenemethoxycarbonyl, azide, phenylthio, and methylthio; Each of the fourth protecting groups is independently selected from: benzyl, tert-butoxycarbonyl, triphenylmethyl, 9-fluorenoxycarbonyl, acetyl, benzyloxycarbonyl, allyloxycarbonyl, phthaloyl, trifluoroacetyl, and p-toluenesulfonyl; Alternatively, two hydroxyl groups on adjacent carbons of the sugar ring are replaced by two third protecting groups, which together form an acetal or ketal structure.

[0015] In one or more embodiments, the acetal structure is formed by the reaction of benzaldehyde and two hydroxyl groups on adjacent carbons of a sugar ring.

[0016] In one or more embodiments, the ketal structure is formed by the reaction of acetophenone and two hydroxyl groups on adjacent carbons of the sugar ring.

[0017] In one or more embodiments, the compound of formula I is selected from compound 8 and compound 1.

[0018] In one or more embodiments, the compound of formula II is selected from compound 11 and compound 2.

[0019] In one or more embodiments, the glycoside is a viral (such as norovirus) binding receptor; preferably, the glycoside is a blood group antigen receptor; more preferably, it is a blood group H1 antigen receptor and / or a blood group H3 antigen receptor.

[0020] In one or more embodiments, the carbohydrate compound is compound 3 or compound 4.

[0021] The sixth aspect of the present invention provides applications selected from the group consisting of: (1) The use of the compound of formula I described in the fifth aspect of the present invention in the preparation of compound 3; (2) The use of the compound of formula II described in the fifth aspect of the present invention in the preparation of compound 4; (3) Use of compound 9, compound 7, or the compound of formula III described in the first aspect of the present invention in the preparation of compound 11; (4) Use of compound 5, compound 7, or the compound of formula III described in the first aspect of the present invention in the preparation of compound 8.

[0022] The present invention has the following advantages: (1) This invention provides a practical and rapid chemical synthesis route for the large-scale acquisition of blood type H1 and H3 antigens and their receptors. The route of this invention uses a photosensitive one-pot method, which has mild reaction conditions, shortens the purification steps, is simple and efficient, environmentally friendly, low cost, and yields high-purity compounds.

[0023] (2) The H1 and H3 blood type receptors obtained in this invention have good binding affinity to norovirus-like particle proteins of different genotypes, which lays the foundation for a deeper understanding of the binding mechanism between norovirus and receptors, and also provides a tool for the development of drugs to prevent and / or treat diseases caused by norovirus. Attached Figure Description

[0024] Figure 1 NMR characterization results of compound 3 (H1-C3-PAA-biot).

[0025] Figure 2 HPLC purity analysis results of compound 3 (H1-C3-PAA-biot).

[0026] Figure 3 NMR characterization results of compound 4 (H3-C3-PAA-biot).

[0027] Figure 4 HPLC purity analysis results for compound 4 (H3-C3-PAA-biot).

[0028] Figure 5 TEM detection of VP1 protein of different genotypes after purification (scale bar is 100 nm).

[0029] Figure 6 : Binding curves of the synthesized H1 receptor with VLPs.

[0030] Figure 7 : Binding curves of the synthesized H3 receptor with VLPs. Detailed Implementation

[0031] It should be understood that, within the scope of this invention, the above-described technical features of this invention and the technical features specifically described below (such as embodiments) can be combined with each other to form preferred technical solutions.

[0032] Those skilled in the art can appropriately select and combine protecting groups based on the stereochemistry (participating or non-participating) of the desired glycosidic bond, the compatibility of subsequent steps, and the final deprotection sequence. Several preferred combinations of protecting groups are shown in the examples, but this does not constitute a limitation on the scope of the invention.

[0033] In this document, "optional" or "optionally" means that the situation or event described below may or may not occur, and the description includes instances where said situation or event occurs and instances where it does not occur. For example, "the solvent includes optional methanol" means that the solvent may or may not include methanol, and the description includes either the solvent including methanol or the solvent not including methanol.

[0034] Exemplary compounds applicable to this invention are shown in Table 1. Those skilled in the art will understand that the compounds listed in Table 1 are specific embodiments of the invention and not limitations thereof.

[0035] Table 1

[0036] In this article, "Cbz" stands for benzyloxycarbonyl, i.e., PhCH2O(CO)-.

[0037] In this article, "Bn" stands for benzyl.

[0038] In this article, "Bz" stands for benzoyl group, i.e., Ph(CO)-.

[0039] compound

[0040] This invention provides a compound of formula I:

[0041] (I)

[0042] In Formula I: Each hydroxyl group may be optionally replaced by a first protecting group; one, two, or three H atoms in NH and NH2 may be optionally replaced by a second protecting group; Each of the first protecting groups is independently selected from: benzyl, p-methoxybenzyl, 3,4-dimethoxybenzyl, triphenylmethyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, triisopropylsilyl, acetyl, benzoyl, neopentanoyl, chloroacetyl, bromoacetyl, benzylene, isopropylene, allyl, allyloxycarbonyl, propargyl, nitroveratroloxy, 9-fluorenemethoxycarbonyl, azide, phenylthio, and methylthio; Each of the second protecting groups is independently selected from: benzyl, tert-butoxycarbonyl, triphenylmethyl, 9-fluorenyloxycarbonyl, acetyl, benzyloxycarbonyl, allyloxycarbonyl, phthaloyl, trifluoroacetyl, and p-toluenesulfonyl; Alternatively, two hydroxyl groups on adjacent carbons of the sugar ring are replaced by two first protecting groups, which together form a ketal or acetal structure.

[0043] Preferably, the acetal structure is formed by the reaction of benzaldehyde and two hydroxyl groups on adjacent carbons of the sugar ring. Preferably, the ketal structure is formed by the reaction of acetophenone and two hydroxyl groups on adjacent carbons of the sugar ring.

[0044] In some embodiments, the compound of formula I is selected from compound 8 and compound 1.

[0045] This invention provides compounds of formula II:

[0046] (II)

[0047] In Formula II: Each hydroxyl group may be optionally replaced by a third protecting group; one, two or three H atoms in NH and NH2 may be optionally replaced by a fourth protecting group; Each of the third protecting groups is independently selected from: benzyl, p-methoxybenzyl, 3,4-dimethoxybenzyl, triphenylmethyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, triisopropylsilyl, acetyl, benzoyl, neopentanoyl, chloroacetyl, bromoacetyl, benzylene, isopropylene, allyl, allyloxycarbonyl, propargyl, nitroveratroloxy, 9-fluorenemethoxycarbonyl, azide, phenylthio, and methylthio; Each of the fourth protecting groups is independently selected from: benzyl, tert-butoxycarbonyl, triphenylmethyl, 9-fluorenoxycarbonyl, acetyl, benzyloxycarbonyl, allyloxycarbonyl, phthaloyl, trifluoroacetyl, and p-toluenesulfonyl; Alternatively, two hydroxyl groups on adjacent carbons of the sugar ring are replaced by two third protecting groups, which together form an acetal or ketal structure.

[0048] Preferably, the acetal structure is formed by the reaction of benzaldehyde and two hydroxyl groups on adjacent carbons of the sugar ring. Preferably, the ketal structure is formed by the reaction of acetophenone and two hydroxyl groups on adjacent carbons of the sugar ring.

[0049] In some embodiments, the compound of formula II is selected from compound 11 and compound 2.

[0050] method

[0051] This invention also provides a method for preparing compound 8 or 11, the method comprising: (1) in a solvent, compound 5 undergoes a first glycosylation reaction with compound III to obtain a first product; (2) removing the photosensitive protecting group from the first product by light irradiation. o NBC, to obtain the second product; (3) the second product undergoes a second glycosylation reaction with compound 7 to obtain compound 8; or, (1') compound 9 undergoes a first glycosylation reaction with compound of formula III to obtain the fourth product; (2') the photosensitive protecting group in the fourth product is removed by light irradiation. o NBC, to obtain the fifth product; (3') the fifth product undergoes a second glycosylation reaction with compound 7 to obtain compound 11; ; ; In Equation III, LG is selected from: , , and ; In Equation III oNBC is o-nitrobenzyloxycarbonyl ( ); The TCA in compound 5 is trichloroacetyl (TCA). ).

[0052] In some embodiments, the compound of formula III is selected from compounds 6a, 6b, 6c, and 6d.

[0053] In some embodiments, the preparation method of compound 8 includes the steps of: glycosylation reaction of compound III and compound 5 in a solvent to obtain a disaccharide protected by a photosensitive protecting group; removing the photosensitive protecting group by light irradiation to generate a disaccharide acceptor with exposed hydroxyl groups in situ; and then glycosylation reaction with compound 7 to obtain compound 8 by a one-pot photosensitive process.

[0054] In some embodiments, the preparation method of compound 11 includes the steps of: glycosylation reaction of compound III and compound 9 in a solvent to obtain a disaccharide protected by a photosensitive protecting group; removing the photosensitive protecting group by light irradiation to generate a disaccharide acceptor with exposed hydroxyl groups in situ; and then glycosylation reaction with compound 7 to obtain compound 11 by a photosensitive one-pot method.

[0055] In some embodiments, the light wavelength used for illumination is 300-400 nm; preferably, the light wavelength is 300 nm, 365 nm or 400 nm; more preferably, the light wavelength is 365 nm.

[0056] In some implementation schemes, the illumination time is 2 to 5 hours.

[0057] In some embodiments, the first glycosylation reaction and / or the second glycosylation reaction may optionally include an activating agent for activating compound III and / or compound 7 to participate in the reaction.

[0058] In this document, the activating reagent is selected from one or more of the following: NIS / TMSOTf, NIS / TBSOTf, NIS / TfOH, NIS / HClO4, NIS / AgOTf, NIS / Ag2CO3, DMTST / MeOTf, TMSOTf, TBSOTf, TfOH, BF3·Et2O, Ph3PAuOTf, Ph3PAuOTf / TfOH, Ph3PAuNTf2, SPhosAuOTf, and SPhosAuNTf2. For example, in the first glycosylation reaction, the activating agent used to activate compound III can be selected from one or more of the following: NIS / TMSOTf, NIS / TBSOTf, NIS / TfOH, NIS / HClO4, NIS / AgOTf, NIS / Ag2CO3, DMTST / MeOTf, TMSOTf, TBSOTf, TfOH, BF3·Et2O, Ph3PAuOTf / TfOH, Ph3PAuNTf2, SPhosAuOTf, Ph3PAuOTf, and SPhosAuNTf2; in the second glycosylation reaction, the activating agent used to activate compound 7 can be selected from one or more of the following: Ph3PAuOTf, Ph3PAuNTf2, SPhosAuOTf, SPhosAuNTf2, NIS / TMSOTf, NIS / TBSOTf, and NIS / TfOH. Preferably, in the first glycosylation reaction, the activating agent used to activate compound III is selected from NIS / TfOH, TMSOTf, TfOH, Ph3PAuOTf, and Ph3PAuOTf / TfOH. Preferably, in the second glycosylation reaction, the activating agent used to activate compound 7 is selected from Ph3PAuOTf. In this document, Ph3PAuOTf is added to the reaction system in the form of a dichloromethane solution; preferably, the concentration of Ph3PAuOTf in the dichloromethane solution is 0.05-0.2M, such as 0.05-0.1, 0.1-0.2M, or 0.08-0.15M.

[0059] In some embodiments, the molar ratio of compound 5 or compound 9 to compound III is 1:(1.0~2.0), preferably 1:(1.5~2.0) or 1:(1.5~1.8).

[0060] In some embodiments, the molar ratio of compound 5 or compound 9 to compound 7 is 1:(3~4), preferably 1:(3~3.5).

[0061] In some embodiments, when the first glycosylation reaction includes an activating agent, the molar ratio of compound 5 or compound 9 to the activating agent is 1:(0.1~6.0), preferably 1:(0.2~4.5), 1:(3~4.5), 1:(0.1~1.0), 1:(0.2~0.5), 1:(0.2~1.0) or 1:(0.5~1.0).

[0062] In some embodiments, when the second glycosylation reaction includes an activating agent, the molar ratio of compound 5 or compound 9 to the activating agent is 1:(0.5~2.5), preferably 1:(0.5~1.5) or 1:(1.0~1.3).

[0063] In some embodiments of step (3) and / or step (3'), if compound 7 is completely consumed and a large amount of the second and / or fifth product remains, compound 7 and optional activating agents are added. In some embodiments, the added activating agents are of the same type as the activating agents added initially. Preferably, the amount of compound 7 added is 1-3 times, for example, 1, 2, or 3 times, or within a range of any two values, such as 1-2 times. Preferably, the amount of each activating agent added is 1-3 times, for example, 1, 2, or 3 times, or within a range of any two values, such as 1-2 times.

[0064] In some embodiments, the first glycosylation reaction further includes a reagent for activating compound III, wherein the reagent for activating compound 6a is one or more of the following compounds: NIS / TMSOTf, NIS / TBSOTf, NIS / TfOH, NIS / HClO4, NIS / AgOTf, NIS / Ag2CO3, DMTST / MeOTf; the reagent for activating compound 6b or compound 6c is one or more of the following compounds: TMSOTf (trimethylsilyl trifluoromethanesulfonate), TBSOTf, TfOH, BF3·Et2O; and the reagent for activating compound 6d is one or more of the following compounds: Ph3PAuOTf, Ph3PAuOTf / TfOH, Ph3PAuNTf2, SPhosAuOTf, SPhosAuNTf2, NIS / TMSOTf, NIS / TBSOTf, NIS / TfOH.

[0065] In some embodiments, the compound of formula III is compound 6a, and the activating agent is... N -Iodosuccinimide and trifluoromethanesulfonic acid, compounds 5, 6a, NThe molar ratio of iodosuccinimide to trifluoromethanesulfonic acid is 1:(1.0~2.0):(1.0~5.0):(0.1~1.0); preferably, the molar ratio of compound 5 to compound 6a is 1:(1.5~1.8); preferably, compound 5 and N The molar ratio of iodosuccinimide is 1:(3~4); preferably, the molar ratio of compound 5 to trifluoromethanesulfonic acid is 1:(0.2~0.5).

[0066] In some embodiments, the compound of formula III is compound 6b, the activating agent is trimethylsilyl trifluoromethanesulfonate, and the molar ratio of compound 5, compound 6b and trimethylsilyl trifluoromethanesulfonate is 1: (1.0~2.0): (0.1~1.0); preferably, the molar ratio of compound 5 to compound 6b is 1: (1.5~1.8); preferably, the molar ratio of compound 5 to trimethylsilyl trifluoromethanesulfonate is 1: (0.2~0.5).

[0067] In some embodiments, the compound of formula III is compound 6c, the activating agent is trimethylsilyl trifluoromethanesulfonate, and the molar ratio of compound 5, compound 6c and trimethylsilyl trifluoromethanesulfonate is 1: (1.0~2.0): (0.1~1.0); preferably, the molar ratio of compound 5 to compound 6c is 1: (1.8~2.0); preferably, the molar ratio of compound 5 to trimethylsilyl trifluoromethanesulfonate is 1: (0.2~0.5).

[0068] In some embodiments, the compound of formula III is compound 6d, the activating agent is triphenylphosphine (trifluoromethanesulfonic acid) gold, and the molar ratio of compound 5, compound 6d, and triphenylphosphine (trifluoromethanesulfonic acid) gold is 1: (1.0~2.0): (0.1~1.0); preferably, the molar ratio of compound 5 to compound 6d is 1: (1.5~1.8); preferably, the molar ratio of compound 5 to triphenylphosphine (trifluoromethanesulfonic acid) gold is 1: (0.5~0.8).

[0069] In some embodiments, the compound of formula III is compound 6a, and the activating agent is... N -Iodosuccinimide and trifluoromethanesulfonic acid, compound 9, compound 6a, N The molar ratio of iodosuccinimide to trifluoromethanesulfonic acid is 1:(1.0~2.0):(1.0~5.0):(0.1~1.0); preferably, the molar ratio of compound 9 to compound 6a is 1:(1.5~1.8); preferably, compound 9 and N The molar ratio of iodosuccinimide is 1:(3~4); preferably, the molar ratio of compound 9 to trifluoromethanesulfonic acid is 1:(0.2~0.5).

[0070] In some embodiments, the compound of formula III is compound 6b, the activating agent is trifluoromethanesulfonic acid, and the molar ratio of compound 9, compound 6b and trifluoromethanesulfonic acid is 1: (1.0~2.0): (0.1~1.0); preferably, the molar ratio of compound 9 to compound 6b is 1: (1.5~1.8); preferably, the molar ratio of compound 9 to trifluoromethanesulfonic acid is 1: (0.3~0.5).

[0071] In some embodiments, the compound of formula III is compound 6c, the activating agent is trifluoromethanesulfonic acid, and the molar ratio of compound 9, compound 6c and trifluoromethanesulfonic acid is 1: (1.0~2.0): (0.1~1.0); preferably, the molar ratio of compound 9 to compound 6c is 1: (1.5~1.8); preferably, the molar ratio of compound 9 to trifluoromethanesulfonic acid is 1: (0.3~0.5).

[0072] In some embodiments, the compound of formula III is compound 6d, the activating agent is triphenylphosphine (trifluoromethanesulfonic acid) gold, and the molar ratio of compound 9, compound 6d, and triphenylphosphine (trifluoromethanesulfonic acid) gold is 1: (1.0~2.0): (0.1~1.0); preferably, the molar ratio of compound 9 to compound 6d is 1: (1.5~1.8); preferably, the molar ratio of compound 9 to triphenylphosphine (trifluoromethanesulfonic acid) gold is 1: (0.3~0.5).

[0073] In some embodiments of step (3), the activating agent is triphenylphosphine (trifluoromethanesulfonic acid) gold, and the molar ratio of compound 5, compound 7 to triphenylphosphine (trifluoromethanesulfonic acid) gold is 1:(3~4):(0.5~2.5); preferably, the molar ratio of compound 5 to compound 7 is 1:(3~3.5); preferably, the molar ratio of compound 5 to triphenylphosphine (trifluoromethanesulfonic acid) gold is 1:(1~1.3).

[0074] In some embodiments of step (3'), the activating agent is triphenylphosphine (trifluoromethanesulfonic acid) gold, and the molar ratio of compound 9, compound 7, and triphenylphosphine (trifluoromethanesulfonic acid) gold is 1:(3~4):(0.5~2.5); preferably, the molar ratio of compound 9 to compound 7 is 1:(3~3.5); preferably, the molar ratio of compound 9 to triphenylphosphine (trifluoromethanesulfonic acid) gold is 1:(0.5~1.5).

[0075] Preferably, the method incorporates molecular sieves for water removal. All molecular sieves used herein are newly activated molecular sieves. In some embodiments, molecular sieves are added in the first glycosylation reaction; and / or, molecular sieves are added in the second glycosylation reaction. This document does not impose particular restrictions on the type, particle size, or grade of molecular sieves, as long as they do not adversely affect the reaction; for example, 3Å, 4Å, or 5Å molecular sieves, preferably 4Å molecular sieves. In some embodiments, the amount of molecular sieve used in the first glycosylation reaction is 10-200 mg / mL; preferably, the amount of molecular sieve used is 20 mg / mL, 30 mg / mL, 50 mg / mL, 60 mg / mL, 70 mg / mL, 80 mg / mL, 90 mg / mL, 100 mg / mL, 120 mg / mL, 150 mg / mL, 200 mg / mL, or within any range of two values, such as 30-60 mg / mL. In some embodiments, the amount of molecular sieve used in the second glycosylation reaction is 30-250 mg / mL; preferably, the amount of molecular sieve used is 30 mg / mL, 50 mg / mL, 60 mg / mL, 70 mg / mL, 80 mg / mL, 90 mg / mL, 100 mg / mL, 120 mg / mL, 150 mg / mL, 200 mg / mL, 230 mg / mL, 250 mg / mL, or within any range of two values, such as 50-100 mg / mL, 50-150 mg / mL, or 50-80 mg / mL.

[0076] In some embodiments, the solvent is selected from one or more of dichloromethane, toluene, tetrahydrofuran, acetonitrile, 1,2-dichloroethane, and pyridine. Preferably, the solvent is dichloromethane or toluene.

[0077] In some embodiments, the method is carried out under the protection of an inert gas, preferably argon or nitrogen.

[0078] In some implementations, the method is carried out at 10-30°C, such as 10°C, 15°C, 20°C, 25°C, 30°C, or between any two values, such as 20-25°C.

[0079] In some embodiments of step (1) and / or step (1'), the reaction time of the first glycosylation reaction is 0.5-5h, for example 1h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, or between any two values, such as 3-4.5h, 4-5h, or 4.5-5h.

[0080] In some embodiments of step (2) and / or step (2'), the reaction time is 1-7h, for example 1h, 2h, 3h, 4h, 5h, 6h, 7h, or between any two values, such as 2-5h, 3-6h, 4-5h.

[0081] In some embodiments of step (3) and / or step (3'), the reaction time of the second glycosylation reaction is 1-48 h, for example 2 h, 5 h, 8 h, 10 h, 12 h, 15 h, 18 h, 20 h, 24 h, 30 h, 36 h, 45 h, 48 h, or between any two values, such as 2-24 h, 2-12 h, or 2-5 h.

[0082] In this paper, to ensure the stereochemical purity of the key glycosidic bond, the present invention introduces a stereodirecting N-trichloroacetamido group into the synthetic route. Specifically, the construction of compound 5 involves and utilizes a glycosyl donor with an N-trichloroacetamido group at the C-2 position. The trichloromethyl group in this protecting group (-NH-CO-CCl3), as one of the strongest known electron-withdrawing groups, significantly reduces the electron density of the amide nitrogen atom through a strong inductive effect. This enhances the stability of the amide bond itself and also profoundly affects its ability to participate as an ortho group: compared to the classical acetamido group, the tendency and ability of the electron-depleted N-trichloroacetamido group to participate in the formation of cyclic oxazoline-onium ion intermediates may be significantly altered. Under preferred reaction conditions (such as the use of specific Lewis acids and solvents), this electronic effect plays a crucial role in regulating the reaction pathway, effectively guiding the glycosylation reaction toward the formation of the desired glycosidic bond and exhibiting good diastereoselectivity. Therefore, N-trichloroacetamido not only serves as a protected form of the amino group, but also as a key structural element that regulates the stereochemistry of glycosidic bonds through remote electronic effects, providing a unique advantage for achieving highly selective synthesis in this invention.

[0083] In this paper, to ensure the stereochemical purity of the key glycosidic bonds, the present invention introduces an azide group without neighboring group involvement in the synthetic route. Specifically, in constructing compound 9, a glycosyl donor with an azide group (-N3) at the C-2 position was designed and used. Since the azide group has no neighboring group involvement, a mixture of α- and β-iodoside intermediates is generated by activating the glycosyl donor with trimethyliodosilane (TMSI). Further addition of triphenylphosphine oxide with the mixed iodoside intermediates forms a highly active β-glycosyl phosphonium iodide salt. The nucleophilic acceptor can only attack from the back side to complete the glycosylation reaction, generating the α-glycoside product. This strategy not only achieves precise stereochemical control, but also allows the azide group to be smoothly converted to an amino group through mild reduction in the later stages of synthesis, thereby efficiently introducing the desired sugar structural unit of the target molecule.

[0084] This article also provides a method for preparing compound 1, the method comprising the steps of: (a) in a solvent, compound 8 is reacted with an intermediate under the action of a base; (b) in a solvent, the intermediate is reacted with hydrogen under the action of a catalyst to obtain compound 1; .

[0085] In some embodiments, the intermediate is a benzoyl-free intermediate.

[0086] In some embodiments of step (a), the base is selected from one or more of the following compounds: sodium methoxide, sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate; preferably, the base is sodium methoxide.

[0087] In some embodiments of step (a), the solvent is selected from one or more of dichloromethane, methanol, ethanol, tetrahydrofuran, dioxane, and water, such as methanol-water mixed solvent, ethanol-water mixed solvent, THF-water mixed solvent, preferably dichloromethane and optionally methanol. In some embodiments, in step (a), the solvent is dichloromethane and methanol, and the volume ratio of dichloromethane to methanol is preferably 1:(5~6).

[0088] In some embodiments of step (a), the molar ratio of compound 8 to base is 1:(5-7); preferably, the molar ratio of compound 8 to base is 1:(5.5~6.5).

[0089] In some embodiments of step (a), the reaction temperature is 10-30°C; preferably, the reaction temperature is room temperature (20-25°C); more preferably, the reaction temperature is 25°C.

[0090] In some embodiments of step (a), the reaction time is 3-10 hours; preferably, the reaction time is 3-5 hours or 5-8 hours.

[0091] Step (b) can further remove benzyl, trichloroacetyl and benzyloxycarbonyl groups from the intermediate.

[0092] Prior to step (b), the intermediates in the reaction solution from step (a) are separated by conventional post-processing methods, such as adjusting the pH of the reaction solution to neutral and then separating by column chromatography. In some embodiments, the pH of the reaction solution from step (a) is adjusted to neutral by acidification. The acid can be any acid conventional in the art that can neutralize the aforementioned base, as long as it does not adversely affect the reaction; for example, the acid can be a hydrogen ion exchange resin.

[0093] In some embodiments of step (b), the catalyst is selected from one or more of palladium on carbon, palladium hydroxide on carbon, and Raney nickel; preferably, the catalyst is palladium on carbon and palladium hydroxide on carbon.

[0094] In this article, the mass fraction of palladium in the catalyst palladium hydroxide carbon is 15-35 wt%, such as 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, or within any range of two values, preferably 15-20 wt%, 20-25 wt%, or 18-22 wt%.

[0095] In this article, the mass fraction of palladium metal in the catalyst palladium on carbon is 5-15 wt%, such as 5 wt%, 10 wt%, 15 wt%, or within any range of two values, preferably 5-10 wt%, 10-15 wt%, or 8-12 wt%.

[0096] In some embodiments of step (b), the mass ratio of compound 8 to the total amount of catalyst is 1:(0.5-5); preferably, the mass ratio of compound 8 to the total amount of catalyst is 1:(0.5-3) or 1:(1.5-3). In some embodiments, the catalyst is palladium hydroxide on carbon and palladium on carbon, with the mass ratio of palladium hydroxide on carbon to compound 8 being 1:(1-1.5), for example 1:(1-1.3), 1:(1-1.2), or 1:(1-1.1), and the mass ratio of palladium on carbon to compound 8 being 1:(1-1.5), for example 1:(1-1.3), 1:(1-1.2), or 1:(1-1.1).

[0097] In some embodiments of step (b), the atmosphere of the reaction system is replaced with hydrogen.

[0098] In some embodiments of step (b), the solvent is selected from one or more of methanol, ethanol, tetrahydrofuran, ethyl acetate, tert-butanol, and water; preferably, the solvent used is a mixed solvent of tert-butanol, tetrahydrofuran, and water; more preferably, in the mixed solvent used, the volume ratio of tert-butanol to water is (3-5):1, such as 4:1, and the volume ratio of tetrahydrofuran to water is (3-5):1, such as 4:1.

[0099] In some embodiments of step (b), the reaction temperature is 10-30°C; preferably, the reaction temperature is room temperature (20-25°C); more preferably, the reaction temperature is 25°C.

[0100] In some embodiments of step (b), the reaction time is 24-72 hours; preferably, the reaction time is 18-30 hours; more preferably, the reaction time is 24-30 hours.

[0101] In some embodiments, the preparation method of compound 1 is as described in any embodiment of this document for compound 8.

[0102] This article also provides a method for preparing compound 2, the method comprising the steps of: (a') in a solvent, reducing the azide group of compound 11 to an amino group under the action of a reducing agent to obtain intermediate A; (b') in a solvent, reacting intermediate A with an amino protecting agent to protect the amino group to obtain intermediate B; (c') in a solvent, reacting intermediate B with a base to obtain intermediate C; (d') in a solvent, reacting intermediate C with hydrogen under the action of a catalyst to obtain compound 2. .

[0103] In some embodiments, the intermediate C is an intermediate with the benzoyl group removed.

[0104] In some embodiments of step (a'), the reducing agent is selected from one or more of the following compounds: zinc powder, acetic acid, triphenylphosphine, 1,3-propanedithiol; preferably, the reducing agent is zinc powder and acetic acid.

[0105] In some embodiments of step (a'), the molar ratio of compound 11 to reducing agent is 1:(40~300); preferably, the molar ratio of compound 11 to reducing agent is 1:(42~200) or 1:(45~50).

[0106] In some embodiments of step (a'), the solvent is selected from one or more of ethanol, tetrahydrofuran, 1,4-dioxane, dichloromethane, toluene, methanol, and acetic acid; preferably, the solvent is one or both of tetrahydrofuran and acetic acid.

[0107] The inventors have discovered that adding acetic acid to the solvent in step (a') can maintain the acidic environment of the reaction system, promote hydrogen transfer, and protect the activity of the reducing agent, thereby improving the selectivity and efficiency of the reaction. In some embodiments of step (a'), the solvent includes acetic acid, and the molar ratio of compound 11 to acetic acid is 1:(20~100); preferably, the molar ratio of compound 11 to acetic acid is 1:(22~100), 1:(25~50), or 1:(25~30).

[0108] In some embodiments of step (a'), the reaction temperature is 10-30°C; preferably, the reaction temperature is room temperature (20-25°C); more preferably, the reaction temperature is 25°C.

[0109] In some embodiments of step (a'), the reaction time is 5-24 hours; preferably, the reaction time is 8-20 or 10-12 hours.

[0110] Before proceeding to step (b'), the intermediates in the reaction solution from step (a') are separated by conventional post-processing methods, such as filtration, washing the reaction solution with saturated NaCl solution, drying with anhydrous Na2SO4, filtration, and concentration under reduced pressure.

[0111] In step (b'), an acid-binding agent is also added, preferably selected from one or more of triethylamine, pyridine, imidazole and potassium carbonate, such as triethylamine.

[0112] In some embodiments of step (b'), the amino protecting agent is acetyl chloride or acetic anhydride; preferably, the agent is acetic anhydride.

[0113] In some embodiments of step (b'), the molar ratio of compound 11 to the acid-binding agent is 1:(50-100), for example 1:(60-95), 1:(70-90) or 1:(80-90).

[0114] In some embodiments of step (b'), the molar ratio of compound 11 to the amino protecting agent is 1:(10-50), for example 1:(15-40), 1:(25-35) or 1:(30-35).

[0115] In some embodiments of step (b'), the acid-binding agent is triethylamine, and the amino-protecting agent is acetic anhydride. The molar ratio of compound 11, acetic anhydride, and triethylamine is 1:(30-70):(30-90), for example, 1:(30-50):(30-90), 1:(30-70):(70-90), or 1:(30-50):(70-90); preferably, the molar ratio of compound 11, acetic anhydride, and triethylamine is 1:31:84.

[0116] In some embodiments of step (b'), the solvent is selected from one or more of dichloromethane, methanol, pyridine, tetrahydrofuran, toluene, 1,2-dichloroethane, trichloromethane, ethyl acetate, and 1,4-dioxane; preferably, the solvent is a mixed solution of dichloromethane and methanol. In some embodiments, the solvent is dichloromethane and methanol, and the volume ratio of dichloromethane to methanol is preferably 1:(8-15), such as 1:(9-13), 1:(10-12), or 1:11.

[0117] In some embodiments of step (b'), the reaction temperature is 10-30°C; preferably, the reaction temperature is room temperature (20-25°C); more preferably, the reaction temperature is 25°C.

[0118] In some embodiments of step (b'), the reaction time is 5-24 hours; preferably, the reaction time is 8-12 or 10-20 hours.

[0119] Before proceeding to step (c'), the intermediates in the reaction solution of step (b') are separated by conventional post-processing methods, such as concentrating the reaction solution under reduced pressure and then separating it by column chromatography.

[0120] In some embodiments of step (c'), the base is selected from one or more of the following compounds: sodium methoxide, sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate; preferably, the base is sodium methoxide.

[0121] In some embodiments of step (c'), the molar ratio of compound 11 to base is 1:(20-70); preferably, the molar ratio of compound 11 to base is 1:(30-70), 1:(40-60), 1:(50-60), or 1:55.

[0122] In some embodiments of step (c'), the solvent is selected from one or more of dichloromethane, methanol, ethanol, tetrahydrofuran, dioxane, and water, preferably methanol-water, ethanol-water, or THF-water; preferably, the solvent is a mixed solution of dichloromethane and methanol. In some embodiments, in step (c'), the solvent is dichloromethane and methanol, and the volume ratio of dichloromethane to methanol is preferably 1:(0.5-2).

[0123] In some embodiments of step (c'), the reaction temperature is 10-30°C; preferably, the reaction temperature is room temperature (20-25°C); more preferably, the reaction temperature is 25°C.

[0124] In some embodiments of step (c'), the reaction time is 5-24 hours; preferably, the reaction time is 8-12 or 10-20 hours.

[0125] Step (d') can further remove benzyl, trichloroacetyl and benzyloxycarbonyl groups from the intermediate.

[0126] Prior to step (d'), the intermediates in the reaction solution from step (c') are separated by conventional post-processing methods, such as adjusting the pH of the reaction solution to neutral and then separating by column chromatography. In some embodiments, the pH of the reaction solution from step (a) is adjusted to neutral by acidification. The acid can be any acid conventional in the art that can neutralize the aforementioned base, as long as it does not adversely affect the reaction; for example, the acid can be a hydrogen ion exchange resin.

[0127] In some embodiments of step (d'), the catalyst is selected from one or more of palladium on carbon, palladium hydroxide on carbon, and Raney nickel; preferably, the catalyst is palladium hydroxide on carbon; more preferably, the catalyst is 15-25% (e.g., 20%) of palladium hydroxide on carbon.

[0128] In some embodiments of step (d'), the mass ratio of compound 11 to catalyst is 1:(0.5-5), such as 1:(1-4), 1:(2-3), 1:(2.5-3), or 1:2.7.

[0129] In some embodiments of step (d'), the atmosphere of the reaction system is replaced with hydrogen.

[0130] In some embodiments of step (d'), the solvent is selected from one or more of methanol, ethanol, tetrahydrofuran, ethyl acetate, tert-butanol, water, and acetic acid; preferably, the solvent is a mixed solution of tetrahydrofuran, water, and acetic acid, and the volume ratio of tetrahydrofuran, water, and acetic acid is (1.3~1.5):1:(0.05~0.06). The inventors have found that adding acetic acid to the solvent in step (d') can maintain the acidic environment of the reaction system, promote hydrogen transfer, and protect the catalyst activity, thereby improving the selectivity and efficiency of the reaction.

[0131] In some embodiments of step (d'), the reaction temperature is 10-30°C; preferably, the reaction temperature is room temperature (20-25°C); more preferably, the reaction temperature is 25°C.

[0132] In some embodiments of step (d'), the reaction time is 12-36 hours; preferably, the reaction time is 24-30 hours.

[0133] In some embodiments, the preparation method of compound 2 is as described in any embodiment herein.

[0134] The present invention also provides a method for preparing compound 3 or 4, comprising the steps of: (A) reacting compound 13 with compound 1 and compound 15 in a solvent in the presence of a base; (B) adding ethanolamine to react and obtain compound 3; or, (A') reacting compound 13 with compound 2 and compound 15 in a solvent in the presence of a base; (B') adding ethanolamine to react and obtain compound 4; ; .

[0135] In some embodiments, the molar ratio of compound 13 to compound 1 is (2~8):1, such as (5~6):1.

[0136] In some embodiments, the molar ratio of compound 13 to compound 15 is (15~25):1, such as (20~25):1.

[0137] In some embodiments, in step (B), an excess of ethanolamine is added to quench the reaction, such as when the molar ratio of compound 13 to compound ethanolamine is 1:(1-1000).

[0138] In some embodiments, the molar ratio of compound 13 to base is 1:(10~20), such as 1:(15~20).

[0139] In some embodiments, the molar ratio of compound 13, compound 1, compound 15 and base is 1:0.2:0.05:(15~30).

[0140] In some embodiments, the base is selected from potassium carbonate, sodium carbonate, cesium carbonate, sodium hydroxide, potassium hydroxide, triethylamine, diisopropylethylamine, pyridine, DBU, DBN, sodium methoxide, sodium ethoxide, potassium tert-butoxide, sodium hydride, and n-butyllithium, preferably triethylamine.

[0141] In some embodiments, the solvent is selected from dichloromethane, tetrahydrofuran, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, methanol, ethanol, 1,4-dioxane, toluene, acetone, and N-methylpyrrolidone; preferably, the solvent is N,N-dimethylformamide.

[0142] In some implementations, the reaction temperature of step (A) is 20-60°C, for example 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, or between any two values, such as 30-50°C.

[0143] In some implementations, the reaction time for step (A) is 24-72 hours, such as 24 h, 32 h, 40 h, 48 h, 56 h, 64 h, 72 h, or between any two values, such as 24-48 h, 40-56 h, or 48-72 h.

[0144] No treatment of the reaction solution is required before proceeding to step (B).

[0145] In some implementations, the reaction temperature of step (B) is 20-60°C, for example 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, or between any two values, such as 30-50°C.

[0146] In some implementations, the reaction time for step (B) is 24-72 hours, such as 24 h, 32 h, 40 h, 48 h, 56 h, 64 h, 72 h, or between any two values, such as 24-48 h, 40-56 h, or 48-72 h.

[0147] In some embodiments, the preparation method of compound 3 is the same as that of compound 1 described in any of the embodiments herein.

[0148] In some embodiments, the molar ratio of compound 13 to compound 2 is (2~8):1, such as (5~6):1.

[0149] In some embodiments, the molar ratio of compound 13 to compound 15 is (15~25):1, such as (20~25):1.

[0150] In some embodiments, in step (B'), an excess of ethanolamine is added to quench the reaction, such as when the molar ratio of compound 13 to compound ethanolamine is 1:(1-1000).

[0151] In some embodiments, the molar ratio of compound 13 to base is 1:(10~20), such as 1:(15~20).

[0152] In some embodiments, the molar ratio of compound 13, compound 2, compound 15 and base is 1:0.2:0.05:(15~30).

[0153] In some embodiments, the base is selected from potassium carbonate, sodium carbonate, cesium carbonate, sodium hydroxide, potassium hydroxide, triethylamine, diisopropylethylamine, pyridine, DBU, DBN, sodium methoxide, sodium ethoxide, potassium tert-butoxide, sodium hydride, and n-butyllithium, preferably triethylamine.

[0154] In some embodiments, the solvent is selected from dichloromethane, tetrahydrofuran, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, methanol, ethanol, 1,4-dioxane, toluene, acetone, and N-methylpyrrolidone; preferably, the solvent is N,N-dimethylformamide.

[0155] In some implementations, the reaction temperature of step (A') is 20-60°C, for example 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, or between any two values, such as 30-50°C.

[0156] In some implementations, the reaction time for step (A') is 24-72 hours, such as 24 h, 32 h, 40 h, 48 h, 56 h, 64 h, 72 h, or between any two values, such as 24-48 h, 40-56 h, or 48-72 h.

[0157] No treatment of the reaction solution is required before proceeding to step (B').

[0158] In some implementations, the reaction temperature of step (B') is 20-60°C, for example 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, or between any two values, such as 30-50°C.

[0159] In some implementations, the reaction time of step (B') is 24-72 hours, such as 24 h, 32 h, 40 h, 48 h, 56 h, 64 h, 72 h, or between any two values, such as 24-48 h, 40-56 h, or 48-72 h.

[0160] In some embodiments, the preparation method of compound 4 is the same as that described in any embodiment herein.

[0161] In some embodiments, the preparation method of compound 13 includes the step of: in a solvent, compound 12 undergoes a polymerization reaction under the action of an initiator to obtain compound 13; .

[0162] In some embodiments, in the method for preparing compound 13 herein, the initiator is a free radical initiator, preferably selected from azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, di-tert-butyl peroxide and tert-butyl peroxide; preferably, the initiator is azobisisobutyronitrile.

[0163] In some embodiments, in the method for preparing compound 13 herein, the molar ratio of compound 12 to the initiator is 1:(0.03~0.05).

[0164] In some embodiments, in the method for preparing compound 13 herein, the solvent is selected from benzene, toluene, ethylbenzene, xylene, cyclohexane, n-hexane, heptane, ethyl acetate, butyl acetate, dichloromethane, chloroform, 1,2-dichloroethane, tetrahydrofuran, and 1,4-dioxane; preferably toluene.

[0165] In some embodiments, the reaction temperature in the method for preparing compound 13 described herein is 50-90°C, for example 50°C, 60°C, 70°C, 80°C, 90°C, or between any two values, such as 60-80°C.

[0166] In some embodiments, the reaction time in the method for preparing compound 13 described herein is 32-72 hours, for example 32h, 40h, 48h, 56h, 64h, 72h, or between any two values, such as 24-56h, 48-64h, or 56-72h.

[0167] In some embodiments, the preparation method of compound 15 includes the steps of: first, in a solvent, under the action of a dehydrating agent, N-hydroxysuccinimide reacts with compound 14 to generate an activated ester; second, in a solvent, under the action of a base, the activated ester reacts with tert-butyl N-(5-aminopentyl)carbamate; and third, a reaction to remove the tert-butyloxycarbonyl group occurs in a solvent to obtain compound 15. .

[0168] In some embodiments, in the first step, the dehydrating agent is selected from EDCI, DCC, DIC, HATU, HBTU, TBTU, BOP, PyBOP, CDI, oxalyl chloride, and thionyl chloride; preferably, the dehydrating agent is DCC.

[0169] In some implementations, in the first step, compound 14 and N The molar ratio of 1-hydroxysuccinimide is 1:(1~3); preferably, compound 14 and... N The molar ratio of 1:(1~2), 1:(1~2.5), or 1:(1~2.8) of hydroxysuccinimide is 1:(1~2).

[0170] In some embodiments, in the first step, the molar ratio of compound 14 to the dehydrating agent is 1:(1~3); preferably, the molar ratio of compound 14 to the dehydrating agent is 1:(1~2), 1:(1~2.5), or 1:(1~2.8).

[0171] In some embodiments, compound 14 is dissolved in a solvent using methods conventional in the art, such as heating, for example, to 70-80°C.

[0172] In some embodiments, the compound 14 is added to a solution containing the compound at 10-30°C (e.g., 20-25°C). N -Hydroxysuccinimide and dehydrating agent.

[0173] In some embodiments, in the first step, the solvent is selected from dichloromethane, N,N-dimethylformamide, tetrahydrofuran, acetonitrile, N-methylpyrrolidone, 1,4-dioxane, dichloroethane, and pyridine; preferably, the solvent is N,N-dimethylformamide.

[0174] In some embodiments, the reaction temperature in the first step is 10-30°C; preferably, the reaction temperature is room temperature (20-25°C); more preferably, the reaction temperature is 25°C.

[0175] In some implementations, the reaction time in the first step is 1-12 hours, such as 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, or between any two values, such as 2-10 h, 8-12 h, 10-12 h.

[0176] Before proceeding to the second step, the activated esters in the reaction solution from the first step are separated by conventional post-processing methods, such as filtering the reaction solution, concentrating the filtrate under reduced pressure, washing with ether, and filtering.

[0177] In some embodiments, in the second step, the base is selected from triethylamine, diisopropylethylamine, N-methylmorpholine, pyridine, potassium carbonate, sodium bicarbonate, and sodium carbonate; preferably, the base is sodium bicarbonate.

[0178] In some embodiments, in the second step, the molar ratio of compound 14 to tert-butyl N-(5-aminopentyl)carbamate is 1:(1-2); preferably, the molar ratio of compound 14 to tert-butyl N-(5-aminopentyl)carbamate is 1:(1~1.8), 1:(1~1.5), or 1:(1~1.2).

[0179] In some embodiments, in the second step, the molar ratio of compound 14 to base is 1:(1-3); preferably, the molar ratio of compound 14 to base is 1:(1~2), 1:(1~2.5), or 1:(1~2.8).

[0180] In some embodiments, in the second step, the solvent is selected from one or more of water, dichloromethane, N,N-dimethylformamide, tetrahydrofuran, acetonitrile, 1,4-dioxane, 1,2-dichloroethane, N-methylpyrrolidone, toluene, and pyridine; preferably, the solvent is a mixture of water and N,N-dimethylformamide, with a volume ratio of N,N-dimethylformamide to water of 1:(1~2), preferably 1:(1~1.8), 1:(1~1.5), or 1:(1~1.2).

[0181] In some embodiments, the reaction temperature in the second step is 10-30°C; preferably, the reaction temperature is room temperature (20-25°C); more preferably, the reaction temperature is 25°C.

[0182] In some implementations, the reaction time in the second step is 1-12 hours, such as 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, or between any two values, such as 2-10 h, 8-12 h, 10-12 h.

[0183] Before proceeding to the third step, the intermediates in the reaction solution from the second step are separated by conventional post-processing methods, such as concentrating the reaction solution under reduced pressure, washing with ether, and filtering.

[0184] In some embodiments, in the third step, the reagent used in the removal of the tert-butyloxycarbonyl group is a trifluoroacetic acid or ethyl acetate hydrochloride solution; preferably, the reagent used is trifluoroacetic acid. The trifluoroacetic acid used herein may be 95% pure trifluoroacetic acid.

[0185] In some embodiments, in the third step, the solvent is selected from dichloromethane, chloroform, 1,2-dichloroethane, tetrahydrofuran, methanol, ethanol, ethyl acetate, acetonitrile, and trifluoroacetic acid; preferably, the solvent is chloroform.

[0186] In some embodiments, in the third step, the reagent used in the removal of tert-butyloxycarbonyl reaction is trifluoroacetic acid, and the volume ratio of trifluoroacetic acid to solvent is 1:(1~5); preferably, the volume ratio of 95% trifluoroacetic acid to chloroform is 1:(1~3), 1:(2~4), or 1:(3~5).

[0187] In some embodiments, the reaction temperature in the third step is 10-30°C; preferably, the reaction temperature is room temperature (20-25°C); more preferably, the reaction temperature is 25°C.

[0188] In some implementations, the reaction time in the third step is 0.1-2 hours, for example 0.1 h, 0.3 h, 0.5 h, 0.7 h, 0.9 h, 1.0 h, 1.2 h, 1.5 h, 1.8 h, 2 h, or between any two values, such as 0.1-0.5 h, 0.2-1 h, 0.5-2 h.

[0189] application

[0190] This article provides the application of compounds of formula I or formula II in the preparation of carbohydrate compounds.

[0191] In some embodiments, the glycoside is a viral (such as norovirus) binding receptor; preferably, the glycoside is a blood group antigen receptor; more preferably, it is a blood group H1 antigen receptor and / or a blood group H3 antigen receptor.

[0192] In some embodiments, the carbohydrate compound is compound 3 or compound 4.

[0193] This article provides the application of compound I in the preparation of compound 3.

[0194] This article provides the application of the compound of formula II in the preparation of compound 4.

[0195] This document provides the use of compound 9, compound III, or compound 7 in the preparation of compound 11, where compound III is defined as described in any embodiment herein.

[0196] This document provides the use of compound 5, compound III, or compound 7 in the preparation of compound 8, where compound III is defined as described in any embodiment herein.

[0197] This invention provides the use of blood group H1 and H3 receptors in the preparation of medicaments for the prevention and / or treatment of diseases caused by norovirus.

[0198] In some implementations, norovirus causes acute gastroenteritis.

[0199] In some implementations, the H1 and H3 receptors can specifically bind to norovirus-like particles.

[0200] In some implementations, norovirus-like particles (VLPs) include subtypes GI.3, GII.2, GII.3, GII.4, GII.6, and GII.17.

[0201] In some implementations, the use is based on the fact that H1 and H3 receptors can bind to norovirus and thus prevent it from entering host cells.

[0202] In some implementations, the method for preparing norovirus-like particles (VLPs) includes the following steps: Pichia pastoris engineered strains with genotypes GI.3, GII.2, GII.3, GII.4, GII.6, and GII.17 are fermented and extracted to obtain virus-like particle proteins (VLPs) expressing various genotypes of VP1. The purified samples are analyzed for purity and protein molecular weight using SDS-PAGE electrophoresis, and protein purity and assembly levels are analyzed using size exclusion chromatography-HPLC, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The fermentation method for the Pichia pastoris engineered strains is consistent with the literature (Chinese Journal of Biological Products, 2020, 33, 1097), and the method for extracting virus-like particle proteins is consistent with Chinese invention patent (CN114085273A).

[0203] In some implementations, the H1 receptor can bind to VLPs of types GI.3, GII.2, GII.3, GII.4, GII.6, and GII.17.

[0204] In some implementations, the H3 receptor can bind to G1.3, G11.3, G11.4 and G11.17 type VLPs.

[0205] In some implementations, the H1 blood type receptor is compound 3, and the H3 blood type receptor is compound 4.

[0206] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. Percentages and parts are by weight unless otherwise stated.

[0207] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0208] In this document, the terms “contains,” “includes,” “containing,” and similar terms encompass the meanings of “basically composed of” and “composed of.” For example, when this document discloses “A contains B and C,” “A is basically composed of B and C” and “A is composed of B and C” should be considered as having been disclosed in this document.

[0209] In this document, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0210] Unless otherwise specified, percentages refer to mass percentages and proportions refer to mass ratios in this article.

[0211] In this document, when describing embodiments or examples, it should be understood that it is not intended to limit the invention to those embodiments or examples. Rather, all alternatives, modifications, and equivalents of the methods and materials described herein are covered within the scope defined by the claims.

[0212] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0213] The first objective of this invention is to provide a method for preparing blood group H1 and H3 antigens and their receptors. The second objective is to provide the use of blood group H1 and H3 antigens and their receptors in the preparation of drugs for the prevention and / or treatment of norovirus-induced diseases. This invention solves the problem of obtaining large quantities of blood group H1 and H3 antigens and their receptors, providing a simple, high-yield, and low-cost chemical synthesis route for these antigens and receptors. This lays the foundation for a deeper understanding of the binding mechanism between norovirus and its receptors and provides a tool for the development of drugs for the prevention and / or treatment of norovirus-induced diseases.

[0214] The structures of all compounds involved in this invention were characterized using NMR and / or HPLC. The NMR measurements were performed using Bruker AVANCE III 400 and Bruker Ascend 600 instruments, and the mass spectrometry measurements were performed using Waters XEVO G2 TOF. The compounds were dissolved in deuterated chloroform, deuterated methanol, deuterated dimethyl sulfoxide, and heavy water. The HPLC measurements were performed using an Agilent 1260 Infinity II instrument, and the compounds were dissolved in water.

[0215] Unless otherwise specified, the reaction temperature is room temperature, and the unit of reaction temperature is degrees Celsius (°C). All reactions in this invention are carried out under continuous magnetic stirring in an anhydrous and oxygen-free reaction environment, and all solvents are anhydrous solvents.

[0216] The following examples are merely illustrative of the implementation process, including but not limited to the conditions therein. The compounds of the present invention can be prepared using suitable substances as raw materials according to the general process described below, and will be specifically illustrated by the following examples. Of course, various known reasonable variations of the conditions and methods for preparing the illustrative compounds in the examples can also be used to prepare these compounds.

[0217] Example 1: One-pot photosensitive synthesis of blood group H1 antigen (compound 1)

[0218] Compound 5 (20.8 mg, 0.03 mmol), compound 6a (32.1 mg, 0.045 mmol), and freshly activated 4 Å molecular sieve (60 mg) were placed in a quartz tube, and dried toluene (2.0 mL) was added to dissolve them. The mixture was stirred at room temperature for 30 min under argon protection. Then, NIS (20.2 mg, 0.09 mmol) and TfOH (5.3 mmol) were added. µThe mixture was stirred for 2 h at room temperature (L, 0.006 mmol). TLC monitoring confirmed the complete reaction of compound 5. The reaction system was then placed in a parallel light reactor and irradiated with a UV flashlight at 300 nm, 365 nm, and 400 nm to remove the photoprotective group. o NBC, TLC confirmed 2 hours later o NBC removal was complete. The quartz tube was transferred to a standard magnetic stirrer, and compound 7 (51.1 mg, 0.09 mmol) and freshly activated 4 Å molecular sieve (150 mg) were added. After stirring at room temperature for 30 min, a freshly prepared dichloromethane solution of PPh3AuOTf (300 mg) was added. µ L, 0.1 M), stirred overnight. After complete conversion of the disaccharide acceptor was confirmed by TLC monitoring, triethylamine was added dropwise to the system for neutralization. After filtering with diatomaceous earth through a molecular sieve, the solvent in the filtrate was removed by vacuum concentration, and then subjected to silica gel column chromatography (petroleum ether / ethyl acetate: 2 / 1) to give white syrupy products: compound 8 (18.4 mg, 300 nm, total yield 42%), (23.7 mg, 365 nm, total yield 54%), and (21.5 mg, 400 nm, total yield 49%).

[0219] Compound 5 (19.4 mg, 0.028 mmol), compound 6b (29.2 mg, 0.042 mmol), and freshly activated 4 Å molecular sieve (50 mg) were placed in a quartz tube, and dried toluene (1.5 mL) was added to dissolve them. The mixture was stirred at room temperature for 30 min under argon protection, and then trimethylsilyl trifluoromethanesulfonate (1.00 mg) was added. µ The mixture was stirred for 2 h at room temperature (L, 0.0056 mmol). TLC monitoring confirmed the complete reaction of compound 5. The reaction system was then placed in a parallel light reactor and irradiated with a UV flashlight at 300 nm, 365 nm, and 400 nm to remove the photoprotective group. o NBC, TLC confirmed 4 hours later o NBC removal was complete. The quartz tube was transferred to a standard magnetic stirrer, and compound 7 (47.7 mg, 0.084 mmol) and freshly activated 4 Å molecular sieve (100 mg) were added. After stirring at room temperature for 30 min, a freshly prepared dichloromethane solution of PPh3AuOTf (280 mg) was added. µAfter 2 h, the disaccharide acceptor was completely converted by TLC monitoring. Triethylamine was then added dropwise to the system for neutralization. After filtering with diatomaceous earth through a molecular sieve, the solvent in the filtrate was removed by vacuum concentration, and then subjected to silica gel column chromatography (petroleum ether / ethyl acetate: 2 / 1) to give white syrupy products: compound 8 (16.4 mg, 300 nm, 40% overall yield), (21.7 mg, 365 nm, 53% overall yield), and (20.5 mg, 400 nm, 50% overall yield).

[0220] Compound 5 (26.6 mg, 0.038 mmol), compound 6c (50.0 mg, 0.0690 mmol), and freshly activated 4 Å molecular sieve (100 mg) were placed in a quartz tube, and dried toluene (2.0 mL) was added to dissolve them. The mixture was stirred at room temperature for 30 min under argon protection, and then trimethylsilyl trifluoromethanesulfonate (1.37 mg) was added. µ The reaction mixture (L, 0.0076 mmol) was stirred for 2 h at room temperature. TLC confirmed the complete reaction of compound 5. The reaction system was then placed in a parallel light reactor and irradiated with a UV flashlight at 300 nm, 365 nm, and 400 nm to remove the photoprotective group. o NBC, TLC confirmed 4 hours later o NBC removal was complete. The quartz tube was transferred to a standard magnetic stirrer, and compound 7 (64.8 mg, 0.114 mmol) and freshly activated 4 Å molecular sieve (200 mg) were added. After stirring at room temperature for 30 min, a freshly prepared dichloromethane solution of PPh3AuOTf (380 mg) was added. µ L, 0.1 M), TLC monitoring after 2 h showed that the donor was completely consumed, but a large amount of disaccharide receptor remained. Compound 7 (64.8 mg, 0.114 mmol) and freshly prepared dichloromethane solution of PPh3AuOTf (380 L, 0.1 M) were added. µ L, 0.1 M), stirred overnight. After TLC monitoring confirmed complete conversion of the disaccharide acceptor, triethylamine was added dropwise to the system for neutralization. After filtering with diatomaceous earth through a molecular sieve, the filtrate was concentrated under vacuum to remove the solvent, and then subjected to silica gel column chromatography (petroleum ether / ethyl acetate: 2 / 1) to give white syrupy products 8 (22.2 mg, 300 nm, total yield 40%), (30.3 mg, 365 nm, total yield 55%), and (44.0 mg, 400 nm, total yield 44%).

[0221] Compound 5 (27.7 mg, 0.04 mmol), compound 6d (41.1 mg, 0.06 mmol), and freshly activated 4 Å molecular sieve (100 mg) were placed in a quartz tube, and dried toluene (2.0 mL) was added to dissolve them. The mixture was stirred at room temperature for 30 min under argon protection, and then a freshly prepared dichloromethane solution of PPh3AuOTf (200 mL) was added. µ L, 0.1 M), stirred at room temperature for 2 h. After confirming complete reaction of receptor 5 by TLC, the reaction system was placed in a parallel light reactor and irradiated with a UV flashlight at 300 nm, 365 nm, and 400 nm to remove the photoprotective group. o NBC, TLC confirmed 4 hours later o NBC removal was complete. The quartz tube was transferred to a standard magnetic stirrer, and compound 7 (68.2 mg, 0.12 mmol) and freshly activated 4 Å molecular sieve (200 mg) were added. After stirring at room temperature for 30 min, a freshly prepared dichloromethane solution of PPh3AuOTf (400 mg) was added. µ After 2 h of TLC monitoring confirming complete conversion of the disaccharide acceptor, triethylamine was added dropwise to the system for neutralization. After filtering with diatomaceous earth through a molecular sieve, the filtrate was concentrated under vacuum to remove the solvent, and then subjected to silica gel column chromatography (petroleum ether / ethyl acetate: 2 / 1) to obtain white syrupy products 8 (26.3 mg, 300 nm, total yield 45%), (31.6 mg, 365 nm, total yield 54%), and (23.4 mg, 400 nm, total yield 40%). = +0.70 ( c 0.72, CHCl3); 1 H NMR (400 MHz, CDCl3) δ 7.85 (d, J =7.5 Hz, 2 H), 7.57–7.50 (m, 4 H), 7.40–7.27(m, 19 H), 7.25–7.21 (m, 5 H), 7.19–6.96 (m, 11 H), 5.54 (s, 1 H), 5.47 (s, 1H), 5.29 (d, J = 3.6 Hz, 1 H), 5.19–5.12 (m, 3 H), 4.91 (d, J = 11.2 Hz, 1H), 4.71 (d, J= 7.6 Hz, 1 H), 4.60 (s, 1 H), 4.55–4.47 (m, 2 H), 4.44–4.28(m, 5 H), 4.27–4.12 (m, 6 H), 4.04–3.93 (m, 1 H), 3.92–3.83 (m, 3 H), 3.80(d, J = 9.2 Hz, 2 H), 3.63 (dd, J = 9.6, 31.6 Hz, 1 H), 3.57–3.36 (m, 4 H),3.31–3.20 (m, 1 H), 3.09 (s, 1 H), 1.79 (d, J = 6.0 Hz, 2 H), 1.18 (s, 3 H); 13 C NMR (150 MHz, CDCl3) δ 192.6, 166.4, 162.5, 138.6, 138.1, 137.9, 137.3,136.6, 134.6, 133.5, 133.2, 130.2, 130.1, 129.9, 129.7, 129.5, 129.2, 128.8,128.7, 128.6, 128.5, 128.4, 128.3, 128.1, 128.0, 127.8, 127.7, 127.5, 127.4,127.3, 126.6, 126.4, 102.1, 101.2, 98.7, 98.3, 92.8, 79.3, 79.1, 76.0, 75.1,75.0, 74.2, 73.6, 73.2, 72.7, 69.1, 69.0, 68.8, 67.8, 67.5, 67.3, 66.9, 66.7,66.3, 63.0, 57.6, 50.8, 44.4, 29.9, 17.3; HRMS (ESI) m / z calcd forC 80 H 81 Cl3N2O 18 Na [M + Na] + 1485.4448, found 1485.4454.

[0222] Compound 8 (270 mg, 0.185 mmol) was dissolved in a mixture of dry dichloromethane (13.0 mL) and methanol (2.2 mL), and sodium methoxide (59.4 mg, 1.10 mmol) was added. The mixture was stirred at room temperature for 5 h. The reaction was confirmed to be complete by TLC. The system was neutralized to pH by adding hydrogen ion exchange resin, the resin was removed by filtration, the mixture was concentrated under vacuum, and then subjected to silica gel column chromatography (petroleum ether / ethyl acetate: 1.5 / 1) to obtain a yellow syrup. The product from the previous step was dissolved in a mixed solvent of tert-butanol, tetrahydrofuran, and water (v / v / v, 16.4 / 4.1 / 4.1, 24.6 mL), and 20% palladium hydroxide on carbon (280 mg) and 10% palladium on carbon (280 mg) were added. The mixture was purged with hydrogen several times and stirred at room temperature for 2 days. TLC monitoring confirmed complete reaction of the raw materials. Palladium hydroxide on carbon and palladium on carbon were removed by filtration membrane. The filtrate was concentrated under vacuum to obtain the crude product, which was then subjected to C... 18 The compound was purified by reversed-phase silica gel column chromatography (anhydrous methanol / water: 2 / 3) to give yellow crystalline compound 1 (86.1 mg, overall yield 79%). = -53.1 ( c 0.63, H2O); 1 H NMR (400 MHz, D2O) δ 5.20 (d, J = 4.0 Hz, 1 H), 4.66 (d, J =7.6 Hz, 1 H), 4.44 (d, J = 8.4 Hz, 1 H), 4.28 (dd, J = 6.0, 12.8 Hz, 1 H),4.05–3.92 (m, 3 H), 3.91–3.88 (m, 1 H), 3.86–3.82 (m, 1 H), 3.81–3.73 (m, 6H), 3.71–3.64 (m, 3 H), 3.59 (t, J = 8.4 Hz, 1 H), 3.55-3.44 (m, 2 H), 3.12-3.03 (m, 2 H), 2.08 (s, 3 H), 1.99-1.89 (m, 2 H), 1.23 (d, J = 6.4 Hz, 1 H); 13C NMR (150 MHz, D2O) δ 173.9, 101.7, 100.2, 99.5, 77.2, 76.6, 75.4, 75.1,73.4, 71.8, 69.4, 69.1, 68.7, 68.0, 67.9, 66.5, 61.1, 60.6, 54.9, 37.4, 26.7,22.1, 15.2; HRMS (ESI) m / z calcd for C 23 H 43 N2O 15 [M + H] + 587.2663, found 587.2665.

[0223] Example 2: One-pot photosensitive synthesis of blood group H3 antigen (compound 2)

[0224] Compound 9 (23.0 mg, 0.04 mmol) and compound 6a (42.8 mg, 0.06 mmol) were placed in a quartz tube, and 4 Å MS (80 mg) and anhydrous CH2Cl2 (2 mL) were added under argon protection. The mixture was stirred at room temperature for 30 min. Then, NIS (27.0 mg, 0.12 mmol) and TfOH (7.08 mmol) were added. µ L, 0.008 mmol), stirred at room temperature for 2 h. After TLC showed complete reaction, the quartz tube was exposed to 300 nm, 365 nm and 400 nm UV flashlight to remove the photosensitive protective group. After 5 h, TLC showed complete reaction. The quartz tube was transferred to a regular stirrer, and 4 Å MS (200 mg) and compound 7 (68.2 mg, 0.12 mmol) were added under argon atmosphere, and stirred at room temperature for 30 min. Freshly prepared Ph3PAuOTf CH2Cl2 solution (400 mmol) was added. µ L, 0.1M), after 2 h TLC showed that the reaction was complete. The reaction solution was quenched with Et3N, filtered with diatomaceous earth, concentrated, and the crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate: 2 / 1) to give white oily product compound 11 (19.4 mg, 300 nm, total yield 36%), (24.2 mg, 365 nm, total yield 45%), and (20.4 mg, 400 nm, total yield 38%).

[0225] Compound 9 (30.3 mg, 0.05 mmol) and compound 6b (54.1 mg, 0.078 mmol) were placed in a quartz tube, and 4 Å MS (90 mg) and anhydrous CH2Cl2 (2 mL) were added under argon protection. The mixture was stirred at room temperature for 30 min. Then, TfOH (1.33 mg / mL) was added. µ L, 0.015 mmol), stirred at room temperature for 2 h. After TLC showed complete reaction, the quartz tube was exposed to 300 nm, 365 nm and 400 nm UV flashlight to remove the photoprotective group. After 5 h, TLC showed complete reaction. The quartz tube was transferred to a regular stirrer, and 4 Å MS (200 mg) and compound 7 (85.2 mg, 0.15 mmol) were added under argon atmosphere, and stirred at room temperature for 30 min. Freshly prepared Ph3PAuOTf CH2Cl2 solution (400 mmol) was added. µ L, 0.1M), after 2 h TLC showed that the reaction was complete. The reaction solution was quenched with Et3N, filtered with diatomaceous earth, concentrated, and the crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate: 2 / 1) to give white oily product compound 11 (21.5 mg, 300 nm, total yield 32%), (30.3 mg, 365 nm, total yield 45%), and (20.2 mg, 400 nm, total yield 30%).

[0226] Compound 9 (20.1 mg, 0.035 mmol) and compound 6c (38.3 mg, 0.053 mmol) were placed in a quartz tube, and 4 Å MS (70 mg) and anhydrous CH2Cl2 (2 mL) were added under argon protection. The mixture was stirred at room temperature for 30 min. Then, TfOH (1.06 mmol) was added. µ L (0.012 mmol), stirred at room temperature for 2 h. After TLC showed complete reaction, the quartz tube was exposed to 300 nm, 365 nm and 400 nm UV flashlight to remove the photosensitive protective group. After 5 h, TLC showed complete reaction. The quartz tube was transferred to a regular stirrer, and 4 Å MS (200 mg) and compound 7 (59.7 mg, 0.105 mmol) were added under argon atmosphere, and stirred at room temperature for 30 min. Freshly prepared Ph3PAuOTf CH2Cl2 solution (350 μL) was added. µL, 0.1M), after 2 h TLC showed that the reaction was complete. The reaction solution was quenched with Et3N, filtered with diatomaceous earth, concentrated, and the crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate: 2 / 1) to give white oily product compound 11 (14.1 mg, 300 nm, total yield 30%), (22.1 mg, 365 nm, total yield 47%), and (16.5 mg, 400 nm, total yield 35%).

[0227] Compound 9 (30.3 mg, 0.05 mmol) and compound 6d (53.5 mg, 0.078 mmol) were placed in a quartz tube, and 4 Å MS (100 mg) and anhydrous CH2Cl2 (2 mL) were added under argon protection. The mixture was stirred at room temperature for 30 min. Then, a freshly prepared CH2Cl2 solution of Ph3PAuOTf (150 mL) was added. µ L, 0.1M) and TfOH (1.33) µ L (0.015 mmol), stirred at room temperature for 2 h. After TLC showed complete reaction, the quartz tube was exposed to 300 nm, 365 nm and 400 nm UV flashlight to remove the photosensitive protective group. After 5 h, TLC showed complete reaction. The quartz tube was transferred to a regular stirrer, and 4 Å MS (200 mg) and compound 7 (42.6 mg, 0.075 mmol) were added under argon atmosphere, and stirred at room temperature for 30 min. Freshly prepared Ph3PAuOTf CH2Cl2 solution (264 μL) was added. µ L, 0.1M), after 2 hours TLC showed that the disaccharide donor was completely consumed, but a large amount of acceptor remained. Compound 7 (85.3 mg, 0.15 mmol) and freshly prepared Ph3PAuOTf CH2Cl2 solution (528 L, 0.1 M) were added. µ The reaction was carried out overnight at 0.1 M (L). TLC showed that the reaction was complete. The reaction solution was quenched with Et3N, filtered through diatomaceous earth, concentrated, and the crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate: 2 / 1) to give white oily products compound 11 (20.2 mg, 300 nm, 30% overall yield), (32.0 mg, 365 nm, 48% overall yield), and (25.5 mg, 400 nm, 38% overall yield). =35.22 ( c 0.57, CHCl3); 1 H NMR (400 MHz, CDCl3) δ 8.00 (d, J= 7.6 Hz, 2 H), 7.54 (m, 3H), 7.45–7.26 (m, 25 H), 7.24–7.18 (m, 4 H), 7.10 (t, J = 7.2 Hz, 1 H), 7.02(t, J = 7.6 Hz, 2 H), 6.90 (d, J = 8.0 Hz, 2 H), 5.59 (s, 1 H), 5.47 (s, 1H), 5.43 (d, J = 3.2 Hz, 1 H), 5.34 (dd, J = 3.2, 9.6 Hz, 1 H), 5.20 (m, 2H), 5.00 (m, 2 H), 4.84 (d, J = 11.6 Hz, 1 H), 4.72 (d, J = 11.6 Hz, 1 H),4.62 (d, J = 11.6 Hz, 1 H), 4.56 (s, 2 H), 4.53–4.38 (m, 5 H), 4.28 (s, 4 H),4.21–4.09 (m, 2 H), 4.09–3.93 (m, 3 H), 3.89 (m, 1 H), 3.81–3.43 (m, 7 H),3.38 (m, 2 H), 1.90 (s, 2 H), 0.90 (d, J = 6.4 Hz, 3 H). 13 C NMR (150 MHz,CDCl3) δ 192.6, 165.9, 139.2, 139.1, 138.3, 137.9, 137.8, 134.6, 133.6,130.0, 129.9, 129.6, 129.2, 129.1, 129.0, 128.8, 128.5, 128.4, 128.3, 128.2,128.1, 128.0, 127.6, 127.5, 127.4, 127.3, 126.4, 126.3, 126.1, 102.2, 100.9,99.4, 97.2, 79.3, 78.5, 75.8, 75.0, 73.3, 73.1, 72.4, 70.7, 69.1, 67.5, 66.8,66.5, 63.5, 59.0, 29.9, 16.4. HRMS (ESI) m / z calcd for C 78 H 80 N4O 17 Na [M + Na] + 1367.5416, found 1367.5413.

[0228] Compound 11 (51.7 mg, 0.038 mmol) was dissolved in redistilled THF (1.20 mL), and AcOH (56.0 mg, 0.038 mmol) was added sequentially. μ L) and freshly activated Zn powder (113 mg, 1.73 mmol) were stirred overnight at room temperature. TLC monitoring showed that the starting material reacted completely. After filtration, the reaction solution was washed with saturated NaCl solution, dried over anhydrous Na2SO4, filtered, concentrated under reduced pressure, and directly added to the next step. The crude product from the previous step was dissolved in a mixed solvent of MeOH / CH2Cl2 (v / v, 1.20 / 0.112, 1.10 mL), and Et3N (448) was added sequentially. μ L) and Ac2O (112) μ The mixture was stirred overnight at room temperature. TLC monitoring showed that the starting material reacted completely. The reaction solution was concentrated under reduced pressure and purified by silica gel column chromatography (dichloromethane / anhydrous methanol: 60 / 1) to obtain colorless crystals. The product from the previous step was dissolved in a mixed solution of CH2Cl2 (2.30 mL) and methanol (2.10 mL), and sodium methoxide (NaOMe) (56.5 mg, 1.05 mmol) was added. The mixture was stirred overnight at room temperature. TLC monitoring showed that the starting material reacted completely. The reaction solution was purified by H2S chromatography. + The pH of the resin system was adjusted to neutral, the filtrate was collected by filtration and concentrated under reduced pressure to obtain white crystals. The crude product from the previous step was dissolved in a mixed solvent of THF and H2O (v / v, 15.7 / 11.9, 27.6 mL), and AcOH (700 mg / L) was added sequentially. μ The reaction mixture was prepared with 20% Pd(OH)2 / C (140 mg), purged with hydrogen five times, and stirred at room temperature for 24 h. TLC monitoring showed that the reaction of the starting material was complete. The mixture was filtered and concentrated under reduced pressure, and purified by LH-20 gel column chromatography (anhydrous methanol / water: 3 / 1) to give colorless syrupy solid compound 2 (19.80 mg, total yield 89%). = +27.62 ( c 0.32, CHCl3); 1 H NMR (400 MHz, D2O) δ 5.23 (d, J = 4.0 Hz, 1 H), 4.88 (m, 1 H), 4.64 (d, J= 7.6 Hz, 1 H), 4.22 (m, 1 H), 4.19–4.06 (m, 3 H), 3.99 (m, 1 H), 3.89 (s, 1 H), 3.81 (m, 7 H), 3.69–3.60 (m, 4 H), 3.52 (m, 1H), 3.11 (m, 2 H), 2.05 (s, 3 H), 1.99–1.88 (m, 2 H), 1.19 (d, J = 6.4 Hz, 3H); 13 C NMR (150 MHz, D2O) δ 177.2, 172.2, 100.6, 97.8, 95.4, 74.7, 73.6,72.4, 72.1, 70.4, 69.3, 68.2, 67.7, 66.6, 65.4, 63.5, 59.9, 59.6, 48.0, 35.7,25.4, 20.4, 14.0; HRMS (ESI) m / z calcd for C 23 H 42 N2O 15 H [M + H] + 587.2663, found 587.2665.

[0229] Example 3: Preparation of Compound 13

[0230] Compound 12 (200 mg, 1.04 mmol) was dissolved in toluene (1.00 mL), purged several times with nitrogen, and AIBN (6.00 mg, 0.037 mmol) was added. The mixture was heated to 70 °C and reacted for 50 h, producing a reddish-brown viscous substance. Monitoring showed that a small amount of the starting material remained. The reaction solution was cooled to room temperature, and a small amount of DMF (0.30 mL) was added, followed by a large amount of anhydrous methanol. A precipitate formed, which was filtered and the residue dried to give a white solid 13 (93.8 mg, 47%). Mw = 27836; 1 H NMR (400 MHz, DMSO- d 6) δ 8.07 (m, 2 H), 7.25 (m, 2 H), 3.02 (m, 1 H), 2.18 (m, 2 H). (Compared with literature...) Langmuir 2023, 39 The spectral data of (5929) are consistent, and it is determined to be the target product compound 13.

[0231] Example 4: Preparation of Compound 15

[0232] Compound 14 (2.05 g, 8.40 mmol) was added to DMF (41.0 mL), heated to 80 °C to dissolve completely, then cooled to room temperature, and then added... N 1,93 g (16.8 mmol) of hydroxysuccinimide and DCC (3.47 g, 16.8 mmol) were stirred overnight at room temperature. TLC monitoring showed the reaction was complete with iodine reagent. The reaction solution was filtered, the filtrate was concentrated under reduced pressure, and washed three times with diethyl ether. The residue was dissolved in DMF (84.0 mL). N 1.70 g (8.40 mmol) of tert-butyl 5-(5-aminopentyl)carbamate was dissolved in 0.1 M NaHCO3 (84.0 mL) aqueous solution and then added to the reaction system. The reaction was allowed to proceed overnight at room temperature. Iodine reagent indicated complete reaction. The reaction solution was concentrated under reduced pressure to give a white solid, which was washed three times with water and dried. The residue was dissolved in a 95% TFA:CHCl3 mixture (70.0 mL, V / V = 1 / 3) and stirred at room temperature for 30 min. Iodine reagent indicated complete reaction. The reaction solution was concentrated under reduced pressure to give a reddish-brown viscous solid, which was washed three times with diethyl ether. A small amount of methanol was added, and the mixture was recrystallized repeatedly. Impurities precipitated. The mixture was filtered, and the filtrate was concentrated under reduced pressure to give a colorless, transparent, viscous solid compound 15 (942 mg, total yield 34%). 1 HNMR (400 MHz, CD3OD) δ 4.46 (m, 1 H), 4.27 (m, 1 H), 3.27 (m,1 H), 3.17 (m, 3H), 2.96–2.81 (m, 3 H), 2.67 (m, 1 H), 2.18 (t, J =7.2 Hz, 2 H), 1.75–1.58 (m,5 H), 1.52 (m, 3 H), 1.45–1.28 (m, 4 H). HRMS (ESI) m / z calcd for C 15 H 29 N4O2S[M + H] + 329.2011; Found 329.2012. Consistent with the spectral data in the literature (Beilstein J. Org. Chem. 2013, 9, 89), it was identified as the target product compound 15.

[0233] Example 5: Preparation of Compound 3

[0234] Compound 13 (247 mg, 1280 mg) µ mol), Compound 1 (150 mg, 256 mol), µ mol) and Et3N (2.67 mL) were dissolved in anhydrous DMF (12.8 mL), and the above solution was added to compound 15 (21.0 mg, 64 mL). µ In a 12.8 mL solution of anhydrous DMF (mol), under argon protection, at 40 °C o The reaction was carried out at C for 48 h. TLC showed that compounds 1 and 15 reacted completely. The reaction was quenched by adding excess ethanolamine to the reaction solution, and then further quenched at 40 °C. o Stirring continued at C for 48 h. After complete quenching, the reaction solution was directly evaporated and concentrated, and purified by LH-20 gel column chromatography (anhydrous acetonitrile / water = 1 / 1) to obtain an orange-yellow solid compound 3 (170.0 mg). The NMR characterization and HPLC purity analysis results of compound 3 are as follows: Figure 1 and Figure 2 .

[0235] Example 6: Preparation of Compound 4

[0236] Compound 13 (361.8 mg, 1875 mg) µ Compound 2 (219.8 mg, 375 mol) µ 1 mol) and Et3N (3.90 mL) were dissolved in anhydrous DMF (18.75 mL), and the above solution was added to compound 15 (30.7 mg, 93.5 mL). µ In anhydrous DMF solution of 18.75 mL (mol), under argon protection, at 40 °C o The reaction was carried out at C for 48 h. TLC showed that compounds 2 and 15 reacted completely. The reaction was quenched by adding excess ethanolamine to the reaction solution, and then further quenched at 40 °C. o Stirring continued at C for 48 h. After complete quenching, the reaction solution was directly evaporated and concentrated, and purified by LH-20 gel column chromatography (anhydrous acetonitrile / water = 1 / 1) to obtain an orange-yellow solid compound 4 (225.7 mg). The NMR characterization and HPLC purity analysis results of compound 4 are as follows: Figure 3 and Figure 4 .

[0237] Example 7: Preparation of Norovirus-like Particles (VLPs)

[0238] Pichia pastoris strains with genotypes GI.3, GII.2, GII.3, GII.4, GII.6, and GII.17 were genetically engineered and then fermented and extracted to obtain virus-like particle proteins (VLPs) expressing various VP1 genotypes. The purity and molecular weight of the purified samples were determined by SDS-PAGE electrophoresis. Protein purity and assembly levels were analyzed by size exclusion chromatography-HPLC, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The results are as follows: Figure 5 The fermentation culture method of the Pichia pastoris engineered strain is consistent with that in the literature (Chinese Journal of Biological Products, 2020, 33, 1097), and the method for extracting virus-like particle proteins is consistent with that in Chinese invention patent (CN114085273A).

[0239] Example 8: Assay of H1 receptor binding to G1.3, G11.2, G11.3, G11.4, G11.6 and G11.17 VLPs

[0240] VLPs of genotypes GI.3, GII.2, GII.3, GII.4, GII.6, and GII.17 were coated onto microplates at 25 °C. After washing, the plates were blocked with 5% skim milk powder, and then different concentrations of synthesized H1 receptor (100 μg / ml, serially diluted 2-fold, for a total of 11 concentrations) were added. The plates were reacted overnight at 2–8 °C, with PBS used as a negative control. At 25 °C, an appropriate amount of diluted AP-conjugated avidin was added, and the reaction was carried out for 2 hours. After color development with PNPP-Na substrate, the absorbance was read at 405 nm using a microplate reader.

[0241] Based on the experimental results, such as Figure 6 The synthesized H1 receptor (compound 3) showed good binding affinity to VLPs of different genotypes. Four-parameter fitting of GI.3, GII.2, GII.3, GII.4, GII.6, and GII.17 ECGs confirmed its binding affinity. 50 The concentrations (ng / ml) were 12.53, 21.02, 26.85, 15.44, 17.53, and 12.94, respectively.

[0242] Example 9: Assay of H3 receptor binding to G1.3, G11.3, G11.4 and G11.17 VLPs

[0243] The same procedure as described above was performed at 25 °C. VLPs of genotypes GI.3, GII.3, GII.4, and GII.17 were coated onto microplates. After washing, the microplates were blocked with 5% skim milk powder, and the synthesized H3 receptor was added for reaction. PBS was used as a negative control. AP-conjugated avidin was then added for reaction, followed by PNPP-Na substrate development. The absorbance was read at 405 nm using a microplate reader.

[0244] Based on the experimental results, such as Figure 7 The synthesized H3 receptor (compound 4) showed good binding affinity to VLPs of different genotypes. Four-parameter fitting of GI.3 and GII.4 type ECGs... 50 The concentrations (ng / ml) were 11.98 and 3.89, respectively.

[0245] It should be noted that the above embodiments are only used to illustrate one technical solution of the present invention and are not intended to limit it. Although the present invention has been described in the above preferred embodiments, those skilled in the art should understand that various changes in form and detail can be made without departing from the spirit and scope of the present invention.

Claims

1. A method for preparing compound 8 or 11, characterized in that, The method includes: (1) In a solvent, compound 5 undergoes a first glycosylation reaction with compound III to obtain the first product; (2) The photosensitive protecting group in the first product is removed by light irradiation. o NBC, to obtain the second product; (3) the second product undergoes a second glycosylation reaction with compound 7 to obtain compound 8; or, (1') Compound 9 undergoes a first glycosylation reaction with compound of formula III to give the fourth product; (2') the photoprotective group in the fourth product is removed by light irradiation. o NBC, to obtain the fifth product; (3') the fifth product undergoes a second glycosylation reaction with compound 7 to obtain compound 11; ； ； In Equation III, LG is selected from: , , and ; In Equation III o NBC is o-nitrobenzyloxycarbonyl; In compound 5, TCA is trichloroacetyl; The first and second glycosylation reactions also include activating agents to activate compound III and / or compound 7 to participate in the reaction; In the first glycosylation reaction, the activating agent used to activate compound III is selected from one or more of the following: NIS / TMSOTf, NIS / TBSOTf, NIS / TfOH, NIS / HClO4, NIS / AgOTf, NIS / Ag2CO3, DMTST / MeOTf, TMSOTf, TBSOTf, TfOH, BF3·Et2O, Ph3PAuOTf / TfOH, Ph3PAuNTf2, SPhosAuOTf, Ph3PAuOTf, and SPhosAuNTf2; and in the second glycosylation reaction, the activating agent used to activate compound 7 is selected from one or more of the following: Ph3PAuOTf, Ph3PAuNTf2, SPhosAuOTf, SPhosAuNTf2, NIS / TMSOTf, NIS / TBSOTf, and NIS / TfOH.

2. The method as described in claim 1, characterized in that, The wavelength of light used in the illumination is 300-400 nm.

3. The method as described in claim 1, characterized in that, The light exposure time is 2 to 5 hours.

4. The method as described in claim 1, characterized in that, The solvent is selected from one or more of dichloromethane, toluene, tetrahydrofuran, acetonitrile, 1,2-dichloroethane, and pyridine.

5. The method as described in claim 1, characterized in that, The method is carried out under the protection of an inert gas.

6. The method as described in claim 1, characterized in that, The method is carried out at 10-30℃.

7. The method as described in claim 1, characterized in that, In step (1) and / or step (1'), the reaction time of the first glycosylation reaction is 0.5-5 h.

8. The method as described in claim 1, characterized in that, In step (2) and / or step (2'), the reaction time is 1-7 h.

9. The method as described in claim 1, characterized in that, In step (3) and / or step (3'), the reaction time of the second glycosylation reaction is 1-48 h.

10. The method as described in claim 1, characterized in that, The molar ratio of compound 5 or compound 9 to compound III is 1: (1.0~2.0).

11. The method as described in claim 1, characterized in that, The molar ratio of compound 5 or compound 9 to compound 7 is 1:(3~4).

12. The method as described in claim 1, characterized in that, In the first glycosylation reaction, the molar ratio of compound 5 or compound 9 to the activating reagent is 1:(0.1~6.0).

13. The method as described in claim 1, characterized in that, In the second glycosylation reaction, the molar ratio of compound 5 or compound 9 to the activating reagent is 1:(0.5~2.5).

14. The method as described in claim 1, characterized in that, The method involves adding molecular sieves to remove water.

15. A method for preparing compound 1, characterized in that, The method includes the following steps: (a) In a solvent, compound 8 is reacted with a base to yield an intermediate; (b) In a solvent, the intermediate reacts with hydrogen under the action of a catalyst to give compound 1; The method further includes preparing compound 8 using the method described in any one of claims 1-14; In step (b), the catalyst is selected from one or more of palladium on carbon, palladium hydroxide on carbon, and Raney nickel; 。 16. The method as described in claim 15, characterized in that, In step (a), the alkali is selected from one or more of sodium methoxide, sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

17. The method as described in claim 15, characterized in that, In step (a), the solvent is selected from one or more of dichloromethane, methanol, ethanol, tetrahydrofuran, dioxane, and water.

18. The method as described in claim 15, characterized in that, In step (a), the molar ratio of compound 8 to the base is 1:(5-7).

19. The method as described in claim 15, characterized in that, In step (a), the reaction temperature is 10-30℃.

20. The method as described in claim 15, characterized in that, In step (a), the reaction time is 3-10 hours.

21. The method as described in claim 15, characterized in that, In step (b), the mass ratio of compound 8 to the total amount of catalyst is 1:(0.5-5).

22. The method as described in claim 15, characterized in that, In step (b), the atmosphere of the reaction system is replaced with hydrogen.

23. The method as described in claim 15, characterized in that, In step (b), the solvent is selected from one or more of methanol, ethanol, tetrahydrofuran, ethyl acetate, tert-butanol and water.

24. The method as described in claim 15, characterized in that, In step (b), the reaction temperature is 10-30℃.

25. The method as described in claim 15, characterized in that, In step (b), the reaction time is 24-72 hours.

26. A method for preparing compound 2, characterized in that, The method includes the following steps: (a') In the solvent, compound 11 reduces the azide group to an amino group under the action of a reducing agent to obtain intermediate A; (b') In the solvent, intermediate A reacts with an amino protecting agent to protect the amino group and obtain intermediate B; (c') In the solvent, intermediate B is reacted with a base to yield intermediate C; (d') In the solvent, under the action of a catalyst, intermediate C reacts with hydrogen to give compound 2; The method further includes preparing compound 11 using the method described in any one of claims 1-14; In step (a'), the reducing agent is selected from one or more of zinc powder, acetic acid, triphenylphosphine, and 1,3-propanedithiol; In step (d'), the catalyst is selected from one or more of palladium on carbon, palladium hydroxide on carbon, and Raney nickel; 。 27. The method as described in claim 26, characterized in that, In step (a'), the molar ratio of compound 11 to reducing agent is 1:(40~300).

28. The method as described in claim 26, characterized in that, In step (a'), the solvent is selected from one or more of ethanol, tetrahydrofuran, 1,4-dioxane, dichloromethane, toluene, methanol, and acetic acid.

29. The method as described in claim 26, characterized in that, In step (a'), the reaction time is 5-24 hours.

30. The method as described in claim 26, characterized in that, In step (b'), an acid-binding agent is also added, which is selected from one or more of triethylamine, pyridine, imidazole and potassium carbonate, and the molar ratio of compound 11 to the acid-binding agent is 1:(50-100).

31. The method as described in claim 26, characterized in that, In step (b'), the amino protecting agent is acetyl chloride or acetic anhydride.

32. The method as described in claim 26, characterized in that, In step (b'), the molar ratio of compound 11 to the amino protecting agent is 1:(10-50).

33. The method as described in claim 26, characterized in that, In step (b'), the solvent is selected from one or more of dichloromethane, methanol, pyridine, tetrahydrofuran, toluene, 1,2-dichloroethane, chloroform, ethyl acetate, and 1,4-dioxane.

34. The method as described in claim 26, characterized in that, In step (b'), the reaction temperature is 10-30℃.

35. The method as described in claim 26, characterized in that, In step (b'), the reaction time is 5-24 hours.

36. The method as described in claim 26, characterized in that, In step (c'), the alkali is selected from one or more of sodium methoxide, sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

37. The method as described in claim 26, characterized in that, In step (c'), the molar ratio of compound 11 to the base is 1:(20-70).

38. The method as described in claim 26, characterized in that, In step (c'), the solvent is selected from one or more of dichloromethane, methanol, ethanol, tetrahydrofuran, dioxane, and water.

39. The method as described in claim 26, characterized in that, In step (c'), the reaction temperature is 10-30℃.

40. The method as described in claim 26, characterized in that, In step (c'), the reaction time is 5-24 hours.

41. The method as described in claim 26, characterized in that, In step (d'), the mass ratio of compound 11 to catalyst is 1:(0.5-5).

42. The method as described in claim 26, characterized in that, In step (d'), the solvent is selected from one or more of methanol, ethanol, tetrahydrofuran, ethyl acetate, tert-butanol, water, and acetic acid.

43. The method as described in claim 26, characterized in that, In step (d'), the reaction temperature is 10-30℃.

44. The method as described in claim 26, characterized in that, In step (d'), the reaction time is 12-36 hours.

45. A method for preparing compound 3 or 4, characterized in that, The method includes the following steps: (A) In a solvent, in the presence of a base, compound 13 reacts with compound 1 and compound 15; (B) ethanolamine is then added to further react, yielding compound 3; the method further includes preparing compound 1 using the method described in any one of claims 15-25; or, (A') In a solvent, in the presence of a base, compound 13 reacts with compound 2 and compound 15; (B') ethanolamine is then added to react and give compound 4; the method further includes preparing compound 2 by any one of claims 26-44; ； ； The compound 15 is .

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