CN113683650B - Preparation method of β-D-(1,4)-mannuronic acid oligosaccharide and intermediate thereof - Google Patents
Preparation method of β-D-(1,4)-mannuronic acid oligosaccharide and intermediate thereof Download PDFInfo
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Abstract
本发明公开了一种经济、高效地制备式IX所示的β‑D‑(1,4)‑甘露糖醛酸寡糖的方法。特别地，本发明以经济易得的1,2,3,4,6‑五‑O‑乙酰基‑D‑吡喃甘露糖(式X)为原料，制备关键中间体化合物I、化合物II和化合物III；将中间体化合物II和III偶联成寡糖受体化合物V，将中间体化合物I和II偶联成寡糖供体化合物VII；将化合物V和化合物VII偶联成寡糖化合物VIII，将寡糖化合物VIII脱除保护基得到β‑D‑(1,4)‑甘露糖醛酸寡糖IX。
The present invention discloses a method for economically and efficiently preparing β-D-(1,4)-mannuronic acid oligosaccharide shown in formula IX. In particular, the present invention uses economically available 1,2,3,4,6-penta-O-acetyl-D-pyranose (formula X) as a raw material to prepare key intermediate compounds I, compound II and compound III; intermediate compounds II and III are coupled to form an oligosaccharide acceptor compound V, intermediate compounds I and II are coupled to form an oligosaccharide donor compound VII; compound V and compound VII are coupled to form an oligosaccharide compound VIII, and the oligosaccharide compound VIII is deprotected to obtain β-D-(1,4)-mannuronic acid oligosaccharide IX.
Description
Technical Field
The invention belongs to the field of organic chemical synthesis, and relates to a preparation method of beta-D- (1, 4) -mannuronic acid oligosaccharide (disaccharide to eicosane).
Background
Beta-D- (1, 4) -mannuronic acid oligosaccharide exists widely in natural products, has the effects of promoting plant root growth, inhibiting bacteria, promoting human keratinocyte generation and the like, can be combined with Toll-like receptors 2 and 4, shows immunoregulation effect (CN 103275133A), and has good curative effect (CN 106344593A) on vascular dementia. The national drug administration approves the market of the mannite capsule for treating the light to moderate Alzheimer's disease on the 11 th and 2 nd 2019, and the main component of the mannite capsule is beta-D- (1, 4) -mannuronate oligosaccharide and derivatives thereof.
At present, beta-D- (1, 4) -mannuronic acid oligosaccharide is mainly obtained by degrading sodium alginate (CN 100508985C), the degradation preparation process has great challenges for controlling the purity and impurities, and development of a preparation process which is efficient, simple in operation and capable of being controlled accurately is urgently needed. The preparation of derivatives of beta-D- (1, 4) -mannuronic acid oligosaccharides by solid phase synthesis (WO 2012138698) or liquid phase synthesis (Codée,Jeroen D.C,van den Bos,Leendert J,de Jong,Ana-Rae,et al.The Stereodirecting Effect of the Glycosyl C5-Carboxylate Ester:Stereoselective Synthesis of β-Mannuronic Acid Alginates[J].Journal of Organic Chemistry,74(1):38-47) has been reported in the literature, wherein the solid phase synthesis is costly, requires high equipment and is not easy to be industrially produced. In addition, the existing liquid phase synthesis method has the problems of low synthesis efficiency, complex removal of protecting groups and the like, and is not easy for industrial production. Therefore, a novel, efficient and process-controllable preparation method of the beta-D- (1, 4) -mannuronic acid oligosaccharide is developed and researched, and the method has important application value and economic value.
Disclosure of Invention
In a first aspect of the present invention, there is provided a process for producing beta-D- (1, 4) -mannuronic acid oligosaccharide, which can produce beta-D- (1, 4) -mannuronic acid oligosaccharide of high purity economically and efficiently. The method comprises the steps of carrying out coupling reaction on a compound V and a compound VII, and selectively removing a protecting group R 3 to generate the compound VIII;
And optionally, removing the protecting group R 2 of the compound VIII at one time to form a beta-D- (1, 4) -mannuronic acid oligosaccharide shown in the formula IX;
Wherein m is an integer from 2 to 18, n and n' are each independently an integer from 0 to 8, R 1 is selected from C 1-8 alkyl, C 6-14 aryl optionally substituted with C 1-8 alkyl, R 2 is a hydroxy protecting group removable by palladium on carbon catalyzed hydrogenation or palladium on carbon catalyzed oxidation, and R 3 is a hydroxy protecting group not removable by palladium on carbon catalyzed hydrogenation or palladium on carbon catalyzed oxidation.
In particular, the invention can be realized by taking economically available 1,2,3,4, 6-penta-O-acetyl-D-mannopyranose (formula X) as a raw material to prepare intermediate compounds I, II and III, coupling the intermediate compounds II and III into an oligosaccharide acceptor compound V, coupling the intermediate compounds I and II into an oligosaccharide donor compound VII, coupling the compound V and the compound VII into an oligosaccharide compound VIII, and removing a protecting group to obtain a final product compound IX, namely beta-D- (1, 4) -mannuronate oligosaccharide. The invention provides an economic and efficient solution for synthesizing the beta-D- (1, 4) -mannuronate oligosaccharide compound with the polymerization degree of 2 to 20, and compared with the process for preparing the oligosaccharide mixture by extraction such as sodium alginate degradation, the solution can obtain the oligosaccharide with single polymerization degree and high purity, thereby laying a solid foundation for further researching the pharmacological biological activity of the oligosaccharide with single polymerization degree.
In a second aspect of the present invention, there is provided key intermediates for the synthesis of β -D- (1, 4) -mannuronic acid oligosaccharides, compound I, compound II, compound III, compound V, compound VII and compound VIII, of the formula:
Wherein,
R 1 is selected from C 1-8 alkyl, C 6-14 aryl optionally substituted by C 1-8 alkyl, preferably R 1 is selected from phenyl, o-tolyl, p-methylphenyl, 4-tert-butyl-2-methylphenyl, 2, 4-di-tert-butylphenyl, methyl or ethyl;
R 2 is a hydroxy protecting group removable by palladium on charcoal catalyzed hydrogenation, preferably R 2 is selected from C 6-14 arylmethyl or allyl, said C 6-14 arylmethyl optionally substituted with C 1-8 alkyl, C 1-8 alkoxy, halogen, more preferably R 2 is selected from benzyl, p-methoxybenzyl, naphthylmethyl, allyl, most preferably R 2 is selected from benzyl;
R 3 is a hydroxy protecting group which is not removable by palladium on charcoal catalyzed hydrogenation, preferably R 3 is selected from C 1-8 alkanoyl, C 1-8 alkoxyacyl, C 6-14 arylacyl, tri (C 1-8 alkyl) silyl, 9-fluorenylmethoxycarbonyl, tri (C 6-14 aryl) methyl, wherein any carbon atom of the C 1-8 alkyl groups in C 1-8 alkanoyl and C 1-8 alkoxyacyl may optionally be oxo-substituted, more preferably R 3 is selected from acetyl, levulinyl, trimethylsilyl, t-butyldimethylsilyl, benzoyl, 9-fluorenylmethoxycarbonyl, or trityl, most preferably R 3 is selected from levulinyl;
R 4 is selected from H, C 1-8 alkyl, C 6-14 aryl;
x is selected from fluorine, chlorine, bromine and iodine;
m is selected from an integer from 2 to 18, preferably m is selected from 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18;
n and n 'are each independently selected from integers from 0 to 8, preferably n and n' are each independently selected from 0, 1,2, 3, 4, 5, 6, 7 or 8.
Drawings
FIG. 1 is a general synthetic route for compound VIII and compound IX.
FIG. 2 shows the synthetic routes of the compounds IX-1 and IX-2.
FIG. 3 shows the synthetic routes of compound IX-3 and compound IX-4.
FIG. 4 is a synthetic route for compound IX-5.
Detailed Description
Unless otherwise indicated, the term "alkyl" as referred to herein may be a straight or branched saturated hydrocarbon group such as methyl, ethyl, propyl, butyl, octyl, isopropyl, t-butyl, sec-pentyl and the like. Alkyl groups may be unsubstituted or substituted with one or more substituents (e.g., halogen, alkoxy, aryl, aralkyl, aralkoxy, and the like). C 1-n alkyl (where n is an integer) refers to alkyl groups containing 1 to n carbon atoms, such as 1 to 18 carbon atoms, 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, and the like.
The term "aryl" refers to a monovalent unsaturated aromatic radical having a single ring (such as phenyl) or a fused ring (such as naphthyl or anthracenyl), optionally substituted with substituents such as halogen (including fluorine, chlorine, bromine, iodine), alkyl, aralkyl, alkoxy, aralkoxy and the like. C 6-n aryl (where n is an integer) refers to aryl having 6 to n carbon atoms, such as phenyl, naphthyl, anthracenyl, or an optionally substituted group thereof.
The first aspect of the present invention relates to a process for preparing a beta-D- (1, 4) -mannuronic acid oligosaccharide according to formula (VIII) or formula (IX),
Comprising the following steps:
Carrying out coupling reaction on the compound V and the compound VII, and selectively removing the protecting group R 3 to generate the compound VIII;
And optionally, removing the protecting group R 2 of the compound VIII at one time to form a beta-D- (1, 4) -mannuronic acid oligosaccharide shown in the formula IX;
Wherein m is an integer from 2 to 18, n and n' are each independently an integer from 0 to 8, R 1 is selected from C 1-8 alkyl, C 6-14 aryl optionally substituted with C 1-8 alkyl, R 2 is a hydroxy protecting group removable by palladium on charcoal catalyzed hydrogenation, and R 3 is a hydroxy protecting group not removable by palladium on charcoal catalyzed hydrogenation.
The coupling reaction is carried out in the presence of a large steric hindrance organic base, diphenyl sulfoxide and a sulfonic anhydride catalyst, and then the 4-position hydroxyl protecting group R 3 and the other-position hydroxyl protecting groups R 2 are sequentially removed to obtain the beta-D- (1, 4) -mannuronate oligosaccharide compound shown as IX. Preferably, the sulfonic anhydride catalyst is selected from the group consisting of methanesulfonic anhydride, trifluoromethanesulfonic anhydride, or p-toluenesulfonic anhydride.
In one embodiment of the present invention, there is provided a method of synthesizing compound V comprising:
Dissolving an intermediate compound II and an intermediate compound III in a proper organic solvent, adding a dry molecular sieve, protecting by nitrogen or argon, adding a sulfonic acid catalyst at a proper temperature, performing a coupling reaction to generate a 1, 4-glycosidic bond, then selectively removing a 4-hydroxyl protecting group to obtain a compound IV, repeating the steps of performing the coupling reaction and selectively removing the 4-hydroxyl protecting group R 3 on the compound IV and the compound II, and optionally repeating the steps of performing the coupling reaction and removing the protecting group on the obtained compound until the compound V is obtained.
In a preferred embodiment of the invention, the organic solvent in the synthesis of compound V is selected from the group consisting of anhydrous dichloromethane, anhydrous tetrahydrofuran, anhydrous diethyl ether, anhydrous N, N-dimethylformamide, anhydrous N, N-dimethylacetamide, anhydrous toluene or anhydrous dimethyl sulfoxide, preferably anhydrous dichloromethane, the sulfonic acid catalyst is selected from the group consisting of methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid or trifluoromethanesulfonic acid trimethylsilyl ester, preferably trifluoromethanesulfonic acid trimethylsilyl ester, the reagent for removing the hydroxyl protecting group in the 4-position is preferably hydrazine acetate, the molar equivalent of hydrazine acetate is 3-8eq, preferably 3-5.5eq, for example 4.3eq.
In one embodiment of the present invention, there is provided a method of synthesizing compound VII comprising:
Dissolving the compound I and the compound II in a proper organic solvent, adding a dry molecular sieve, protecting with nitrogen or argon, adding a sulfonic acid catalyst at a proper temperature, performing a coupling reaction to generate a1, 4-glycosidic bond, then selectively removing a 4-hydroxyl protecting group R 3 to obtain a compound VI, repeating the steps of performing the coupling reaction and selectively removing the 4-hydroxyl protecting group R 3 on the compound VI and the compound II, and optionally repeating the steps of performing the coupling reaction and removing the protecting group on the obtained compound until the compound VII is obtained.
In a preferred embodiment of the invention, the organic solvent in the synthesis of compound VII is selected from the group consisting of anhydrous dichloromethane, anhydrous tetrahydrofuran, anhydrous diethyl ether, anhydrous N, N-dimethylformamide, anhydrous N, N-dimethylacetamide, anhydrous toluene or anhydrous dimethyl sulfoxide, preferably anhydrous dichloromethane, the sulfonic acid catalyst is selected from the group consisting of methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid or trifluoromethanesulfonic acid trimethylsilyl ester, the sulfonic acid catalyst is preferably trifluoromethanesulfonic acid trimethylsilyl ester, and the agent for removing the hydroxy protecting group in the 4-position is preferably hydrazine acetate.
In one embodiment of the present invention, there is provided a method of synthesizing compound IX comprising:
Dissolving a compound V and a compound VII in a proper organic solvent, adding a dry molecular sieve, protecting by nitrogen or argon, adding a large steric hindrance organic base, diphenyl sulfoxide and sulfonic anhydride at a proper temperature for catalysis, performing a coupling reaction to generate a 1, 4-glycosidic bond, selectively removing a protective group R 3 of a 4-position hydroxyl group to obtain a compound VIII, adding palladium carbon (the palladium content is 5% -10%) into the compound VIII, and hydrogenating to remove all R 2 protective groups of the compound VIII to obtain the beta-D- (1, 4) -mannuronate oligosaccharide compound IX.
In a preferred embodiment of the invention, the molar ratio of compound V to compound VII in the synthesis of compound IX is 1:0.9, the solvent for the coupling reaction is selected from anhydrous dichloromethane, anhydrous tetrahydrofuran, anhydrous diethyl ether, anhydrous N, N-dimethylformamide, anhydrous N, N-dimethylacetamide, anhydrous toluene or anhydrous dimethyl sulfoxide, preferably anhydrous dichloromethane, the highly sterically hindered organic base is selected from 1, 8-diazabicycloundec-7-ene, 2, 6-di-tert-butylpyridine or 2,4, 6-tri-tert-butylpyrimidine, preferably 2, 6-di-tert-butylpyridine, the sulfonic anhydride catalyst is selected from methanesulfonic anhydride, trifluoromethanesulfonic anhydride or p-toluenesulfonic anhydride, preferably trifluoromethanesulfonic anhydride, the molar equivalent of the sulfonic anhydride is preferably 0.05eq, the reaction temperature is preferably-60 ℃, the reagent for removing the hydroxy protecting group in the 4-position is preferably hydrazine acetate, the molar equivalent is preferably 4.3eq, and the temperature for removing the protecting group is preferably 25 ℃.
The starting compounds used hereinabove of formula I and formula II may be obtained from the compounds of formula X, respectively.
The compounds of formula X are 1-5 substituted mannopyranoses, wherein the substituents may be C 1-C6 acyl groups, such as formyl, acetyl, propionyl. An example of a compound of formula X is 1,2,3,4, 6-penta-O-acetyl-D-mannopyranose.
In a preferred embodiment of the present invention, starting from the simple and readily available starting material 1,2,3,4, 6-penta-O-acetyl-D-mannopyranose (compound of formula X), the overall reaction scheme is as follows:
Wherein R 5 is an acyl group of C 1-8, preferably acetyl.
In one embodiment of the present invention, there is provided a process for synthesizing intermediate compound I comprising:
Step 1, reacting 1,2,3,4, 6-penta-O-acetyl-D-mannopyranose with an anomeric carbon protective agent R 1 SH, and then carrying out alkaline hydrolysis reaction to obtain a compound A;
step 2, selectively protecting hydroxyl groups at the 2-position and the 3-position of the compound A to obtain a compound B;
step 3, oxidizing the hydroxyl at the 6-position of the compound B into carboxyl, and esterifying the carboxyl to obtain the compound I.
In a preferred embodiment, the method comprises:
Step 1, in a dry organic solvent, taking 1,2,3,4, 6-penta-O-acetyl-D-mannopyranose as a raw material, stirring at a proper temperature in the presence of an acid catalyst, adding a proper isocephalic carbon protective agent R 1 SH for reaction under the protection of nitrogen or argon, and then carrying out alkali hydrolysis to obtain a compound A;
step 2, under the catalysis of Lewis acid, selecting proper hydroxyl protecting groups, selectively protecting the hydroxyl groups at the 4-position and the 6-position of the compound A, then selectively protecting the hydroxyl groups at the 2-position and the 3-position, and finally selectively removing the protecting groups at the 4-position and the 6-position to obtain a compound B;
And 3, adding an oxidant into the compound B, selectively oxidizing the hydroxyl at the 6-position of the compound B into carboxyl, and reacting with an alkylating reagent in a proper temperature and a solvent under alkaline conditions to obtain the compound I.
In a more preferred embodiment, the synthesis of intermediate compound I employs a one-pot two-step reaction, without isolation and purification of the intermediate. Wherein the organic solvent in step 1 is selected from anhydrous dichloromethane, anhydrous tetrahydrofuran, anhydrous toluene, anhydrous N, N-dimethylformamide or anhydrous N, N-dimethylacetamide, the proper temperature is 0-25 ℃, preferably 0-5 ℃, the acidic catalyst is selected from boron trifluoride diethyl ether, acetyl chloride or hydrogen chloride gas, preferably boron trifluoride diethyl ether, the molar equivalent of boron trifluoride diethyl ether is preferably 0.1eq, the base is selected from sodium ethoxide, potassium ethoxide, magnesium ethoxide, sodium methoxide, potassium methoxide or magnesium methoxide, preferably sodium methoxide, the molar equivalent of sodium methoxide is preferably 0.1eq, the solvent for alkaline hydrolysis is selected from methanol, ethanol or tetrahydrofuran, preferably methanol, the isohead carbon protectant added in the reaction is selected from thiophenol, o-tolylthiol, p-tolylthiol, 4-tert-butyl-2-methyl thiophenol, 2, 4-di-tert-butyl thiophenol, methyl mercaptan or ethyl mercaptan, preferably p-methyl thiophenol, and the molar equivalent of isohead carbon protectant is preferably 1.05eq.
Wherein the protective agent for protecting the hydroxyl groups at the 4-position and the 6-position of the compound A in the step 2 is selected from the group consisting of benzene dicarboxylacetal, p-methoxy benzene dicarboxylal or 2, 2-dimethoxy propane (acetonylidene), preferably benzene dicarboxylal, the molar equivalent of benzene dicarboxylal is preferably 0.9eq, the Lewis acid catalyst is selected from the group consisting of p-toluene sulfonic acid, trifluoromethane sulfonic acid, aluminum trichloride and ferric trichloride, preferably ferric trichloride, and the protective agent for protecting the hydroxyl groups at the 2-position and the 3-position of the compound A is selected from the group consisting of bromobenzyl, chlorobenzyl, p-methoxy bromobenzyl, p-methoxy chlorobenzyl or allyl bromide, preferably bromobenzyl, and the equivalent of bromobenzyl is preferably 1.9eq.
Wherein the oxidant in the step 3 is selected from tetramethyl piperidine nitrogen oxide, sodium hypochlorite, potassium bromide, hydrogen peroxide, tertiary butyl hydroperoxide or iodobenzene diacetate, preferably tetramethyl piperidine nitrogen oxide or iodobenzene diacetate; the molar equivalent of tetramethylpiperidine nitroxide is preferably 0.2eq, or the molar equivalent of iodobenzene diacetate is preferably 2.5eq, the organic solvent is selected from any one or more of dichloromethane, acetonitrile, water, tetrahydrofuran, N-dimethylformamide or N, N-dimethylacetamide, preferably selected from acetonitrile-water mixed solvent (volume ratio of acetonitrile to water is about 5:1 to 1:5), tetrahydrofuran-water mixed solvent (volume ratio of tetrahydrofuran to water is about 5:1 to 1:5), or dichloromethane-water mixed solvent (volume ratio of dichloromethane to water is about 5:1 to 1:5), more preferably dichloromethane-water mixed solvent (volume ratio of dichloromethane to water is about 1:2), the oxidation reaction temperature is 0 ℃ to 25 ℃, preferably 25 ℃, the base is selected from potassium carbonate, cesium carbonate, sodium carbonate, calcium carbonate, silver carbonate, triethylamine or diisopropylethylamine, preferably potassium carbonate or triethylamine, the molar equivalent of base is preferably 0.5eq to 3, more preferably 1:1 to 1eq, more preferably 1.5, the methoxymethyl bromide, N-bromomethyl-acetic acid, N-bromomethyl-amide or the methoxybenzyl-acetic acid amide is preferably selected from the group consisting of bromomethyl-acetic acid, N-bromomethyl-acetic acid, N-bromoacetic acid, N-methyl-acetic acid or N, N-acetic acid, N-methyl-acetic acid is preferably 0, preferably acetone, the alkylation reaction is carried out at a temperature of 25 ℃ to 100 ℃, preferably at a temperature of 30 ℃.
In one embodiment of the present invention, there is provided a process for synthesizing intermediate compound II comprising:
Step 1, protecting the 4-hydroxyl of a compound I to obtain a compound D;
Step 2, selectively removing the anomeric carbon protecting group-SR 1 of the compound D to obtain a compound E;
Step 3, compound E is reacted with CX 3 CN or CX 3C(＝NR4) X under alkaline conditions to obtain compound II.
In a preferred embodiment, the method comprises:
Step 1, in a dry organic solvent, protecting the 4-hydroxyl of a compound I by using a proper protecting agent under alkaline conditions to obtain a compound D;
Step 2, selectively removing the anomeric carbon protecting group-SR 1 of the compound D to obtain a compound E;
Step 3. Compound E is reacted with CX 3 CN or CX 3C(＝NR4) X (e.g., trichloroacetonitrile) in a dry organic solvent under basic conditions to give Compound II.
In a more preferred embodiment, the synthesis of intermediate compound II employs a one-pot three-step reaction, without isolation and purification of the intermediate. Wherein the suitable protecting agent in step 1 is selected from acetyl chloride, acetic anhydride, trimethylchlorosilane, tert-butyldimethylsilyl chloride, benzoyl chloride, 9-fluorenylmethyl chloroformate, triphenylchloromethane, levulinyl chloride or levulinic acid, preferably levulinic acid, the molar equivalent of the protecting agent is preferably 1.5eq, the organic solvent is selected from anhydrous dichloromethane, anhydrous tetrahydrofuran, anhydrous ethyl acetate, anhydrous acetonitrile, anhydrous toluene, anhydrous N, N-dimethylformamide or anhydrous N, N-dimethylacetamide, preferably anhydrous dichloromethane, the preferred reaction temperature is 25 ℃, the base is selected from anhydrous potassium carbonate, anhydrous sodium carbonate, triethylamine, N-p-dimethylaminopyridine or pyridine, preferably N, N-p-dimethylaminopyridine, and the molar equivalent of the base is preferably 1.5eq.
Wherein the reagent for removing the anomeric carbon protecting group in the step 2 is selected from N-chlorosuccinimide or N-bromosuccinimide, preferably N-bromosuccinimide, and the reaction temperature is preferably 25 ℃.
Wherein the organic solvent in the step 3 is selected from anhydrous dichloromethane, anhydrous tetrahydrofuran, anhydrous ethyl acetate, anhydrous acetonitrile, anhydrous toluene, anhydrous N, N-dimethylformamide or anhydrous N, N-dimethylacetamide, preferably anhydrous dichloromethane, the reaction temperature is preferably 0-10 ℃, the base is selected from anhydrous potassium carbonate, anhydrous sodium carbonate, triethylamine, 1, 8-diazabicyclo [5.4.0] undec-7-ene, N-p-dimethylaminopyridine or pyridine, preferably 1, 8-diazabicyclo [5.4.0] undec-7-ene, and the molar equivalent of the base is preferably 0.5eq.
In one embodiment of the present invention, there is provided a process for synthesizing intermediate compound III comprising:
Step 1, protecting the 4-hydroxyl of a compound I to obtain a compound D;
Step 2, reacting a compound D with R 2 OH under an alkaline condition to obtain a compound F;
And 3, selectively removing the 4-hydroxyl protecting group R 3 of the compound F to obtain a compound III.
In a preferred embodiment, the method comprises:
Step 1, in a dry organic solvent, protecting the 4-hydroxyl of a compound I by using a proper protecting agent under alkaline conditions to obtain a compound D;
step 2, adding R 2 OH, diphenyl thiophenol and a sulfonic anhydride catalyst into a compound D in a dry organic solvent in the presence of a large steric hindrance base, and reacting to obtain a compound F;
and 3, selectively removing the 4-hydroxyl protecting group of the compound F in an organic solvent to obtain a compound III.
In a more preferred embodiment of the present invention, the synthesis of intermediate compound III employs a one-pot three-step process. Wherein the suitable protecting agent in step 1 is selected from acetyl chloride, acetic anhydride, trimethylchlorosilane, tert-butyldimethylsilyl chloride, 9-fluorenylmethyl chloroformate, benzoyl chloride, triphenylchloromethane, levulinyl chloride or levulinic acid, preferably levulinic acid, the molar equivalent of the protecting agent is preferably 1.5eq, the organic solvent is selected from anhydrous dichloromethane, anhydrous tetrahydrofuran, anhydrous ethyl acetate, anhydrous acetonitrile, anhydrous toluene, anhydrous N, N-dimethylformamide or anhydrous N, N-dimethylacetamide, preferably anhydrous dichloromethane, the reaction temperature is preferably 25 ℃, the base is selected from anhydrous potassium carbonate, anhydrous sodium carbonate, triethylamine, N-p-dimethylaminopyridine or pyridine, preferably N, N-p-dimethylaminopyridine, and the molar equivalent of the base is preferably 1.5eq.
Wherein the organic solvent in the step 2 is selected from anhydrous dichloromethane, anhydrous tetrahydrofuran, anhydrous diethyl ether, anhydrous N, N-dimethylformamide, anhydrous N, N-dimethylacetamide, anhydrous toluene or anhydrous dimethyl sulfoxide, preferably anhydrous dichloromethane, the organic base with large steric hindrance is selected from 1, 8-diazabicyclo undec-7-ene, 2, 6-di-tert-butylpyridine or 2,4, 6-tri-tert-butylpyrimidine, preferably 2, 6-di-tert-butylpyridine, the molar equivalent of the base is preferably 2.2eq, the sulfonic anhydride catalyst is selected from methanesulfonic anhydride, trichloromethanesulfonic anhydride, tribromomethanesulfonic anhydride, trifluoromethanesulfonic anhydride or toluenesulfonic anhydride, preferably trifluoromethanesulfonic anhydride, the molar equivalent of the trifluoromethanesulfonic anhydride is preferably 0.05eq, and the reaction temperature is preferably-60 ℃.
Wherein the organic solvent in the step 3 is dichloromethane and/or pyridine, preferably dichloromethane: pyridine=5:1 (V/V), and the reagent for selectively removing the 4-hydroxyl protecting group of the compound F is preferably hydrazine acetate, and the equivalent is preferably 4.3eq.
In a preferred embodiment of the present invention, the compound I, the compound II and the compound III are compounds I-1, II-1 and III-1 respectively represented by the following structural formulas:
The invention has the advantages that:
The method for preparing beta-D- (1, 4) -mannuronic acid oligosaccharide (compound IX) adopts a convergent synthesis strategy, and an oligosaccharide donor (compound VII) and an oligosaccharide acceptor (compound V) are assembled into an oligosaccharide compound VIII with higher sugar numbers through brand-new oligosaccharide intermediates of compound I, compound II and compound III, and a protecting group R 2 in the compound VIII is removed again to synthesize the beta-D- (1, 4) -mannuronic acid oligosaccharide (compound IX). Compared with the prior art, the preparation method provided by the invention is more concise, economical and efficient.
Examples
The invention will be further illustrated with reference to specific examples. It is to be understood that these examples are illustrative of the present invention and are not intended to limit the scope of the present invention. The experimental procedures, which do not address the specific conditions in the examples below, are generally carried out under conventional conditions or under conditions recommended by the manufacturer.
The following examples section provides further illustration of the invention in terms of the total synthesis of disaccharides (compound IX-1), tetrasaccharides (compound IX-2), trisaccharides (compound IX-3), pentasaccharides (compound IX-4) and heptasaccharides (compound IX-5) of beta-D- (1, 4) -mannuronic acid, but the invention is not limited thereto.
The starting materials or reagents used in the examples were obtained commercially, unless otherwise specified.
Room temperature in the examples refers to 20-30 ℃.
Atmospheric pressure in the examples refers to 1 atmosphere.
The water in the examples refers to deionized water.
Meaning of abbreviations
| Abbreviations | Meaning of |
| TLC | Thin layer chromatography |
| EA | Acetic acid ethyl ester |
| Hex | Hexane |
| DCM | Dichloromethane (dichloromethane) |
| TEMPO | Tetramethyl piperidine nitroxide |
| DIC | Diisopropylcarbodiimide |
| DMAP | Dimethylaminopyridine |
| NBS | Bromosuccinimide |
| DBU | 1, 8-Diazabicyclo undec-7-ene |
| TTBP | 2,4, 6-Tri-tert-butylpyridine |
| Tf2O | Trifluoro methane sulfonic anhydride |
| LevOH | Levulinic acid |
| TMSOTf | Trimethylsilicone triflate |
| CNCCl3 | Trichloroacetonitrile |
| min | Minute (min) |
| mL | Milliliters of (milliliters) |
| mmol | Millimoles (milli) |
EXAMPLE 1 Synthesis of Compound I-1
In the first step, 1,2,3,4, 6-penta-O-acetyl-D-mannopyranose (19.5 g,50.0 mmol) was weighed into a 500mL eggplant-type bottle, anhydrous methylene chloride (150 mL) was added, the solution was colorless and transparent, and p-toluene thiophenol (6.2 g,50.0 mmol) and boron trifluoride diethyl etherate (12.7 mL,100 mmol) were added under ice bath. After stirring for half an hour in an ice bath, stirring was continued for 24 hours at room temperature, and the solution turned from pale yellow to pink. TLC (EA/Hex=1/2) detects the disappearance of the raw material, quench the reaction with saturated NaHCO 3 solution, separate the dichloromethane layer by a separating funnel, evaporate the solvent under reduced pressure, then add 200mL of anhydrous methanol for redissolution, add sodium methoxide (256 mg,4.7 mmol), stir at room temperature for 12 hours, detect the complete reaction of the raw material by TLC (EA/Hex=1/2), dilute hydrochloric acid adjusts pH to neutral, evaporate the solvent under reduced pressure, then add dichloromethane (100 mL) and water (100 mL), stir at room temperature for half an hour, separate the water layer by a separating funnel, evaporate water under reduced pressure, and obtain crude compound A-1 which is directly used in the next step without purification.
In a second step, crude compound A-1 (about 47.3 mmol) was dissolved in 200mL anhydrous DMF and PhCH (OMe) 2 (7.9 g,52.03mmol,1.1 eq), p-toluene sulfonic acid (899 mg, 4.7mmol,0.1 eq), reaction temperature controlled at 50℃and reduced pressure for 2 hours, TLC (CH 3 OH/DCM=1/9) indicated complete reaction of the starting material. After cooling the reaction to room temperature and adding NaH (5.68 g,141.9mmol,3.0 eq) under ice bath for 20min, bnBr (20.2 g,118.3mmol,2.5eq) was added, after 20min the ice bath was removed and stirred at room temperature for 12 h, TLC (EA/hex=1/4) indicated complete conversion of the starting material. NaH was quenched with methanol (10 mL) in an ice bath, the reaction was diluted with ethyl acetate (200 mL), washed three times with saturated brine (200 mL), concentrated under reduced pressure to remove the solvent, redissolved with 300mL of methanol, and reacted with p-toluene sulfonic acid (899 mg, 10%) at room temperature for 12 hours, TLC (EA/hex=1/9) indicated complete reaction of the starting materials. The reaction solution was then adjusted to pH 8 with saturated sodium bicarbonate solution, the organic layer was separated in a separating funnel, the solvent was removed under reduced pressure, and the mixture was purified by column chromatography, eluting with the ratio (EA/hex=1/12-CH 3 OH/dcm=1/9), the organic phase was dried by spinning, and the mixture was evacuated to constant weight to give compound B-1 (11.8 g,25.5 mmol) as a white solid in 51% yield (as acetylmannose). The nuclear magnetic data are shown below:
1H NMR(600MHz,CDCl3)δ7.37–7.21(m,12H),7.06(d,J＝7.9Hz, 2H),5.45(d,J＝1.3Hz,1H),4.60(d,J＝12.2Hz,1H),4.57–4.46(m,3H), 4.17–4.00(m,2H),3.94(dd,J＝3.0,1.5Hz,1H),3.85–3.73(m,2H),3.68(dd,J＝9.1,3.1Hz,1H),3.35(s,1H),2.70(d,J＝3.7Hz,1H),2.28(s,3H).
In a third step, compound B-1 (6.3 g,13.6 mmol) was weighed into a 250mL eggplant-type bottle, 87mL of a mixed solution of water and methylene chloride (v/v=1/2) was added and the mixture was colorless and transparent, TEMPO (424 mg,2.7mmol,0.2 eq) was added, the solution turned reddish brown, phI (OAc) 2 (10.9 g,33.9mmol,2.5 eq) was added, and the mixture was vigorously stirred at room temperature for 3 hours, the solution turned brown, and TLC (EA/Hex=1/1) indicated that the reaction of the starting material was complete. To the reaction solution was added saturated aqueous Na 2S2O3 (10 mL), ph=3 was adjusted with dilute hydrochloric acid, stirred for 10 minutes, 100mL of the extract was added, the solvent was removed under reduced pressure, 180mL of acetone was added again for reconstitution, bnBr (4.6 g,27.2mmol,2 eq), K 2CO3 (2.8 g,20.4mmol,1.5 eq) and the reaction was stirred at room temperature under nitrogen protection for 3 hours, the solution was reddish brown, TLC (CH 3 OH/dcm=1/9) indicated complete disappearance of the starting material, the reaction solution was adjusted to neutral with dilute hydrochloric acid, the extract was separated with dichloromethane (100 mL), the organic phase was concentrated under reduced pressure, and the column chromatography was purified (EA/hex=1/10-1/1) to give compound I-1 (4.3 g,7.5 mmol) as a reddish-brown oil with a yield of 55% (based on compound B-1). Nuclear magnetic pattern data are shown below:
1H NMR(600MHz,CDCl3)δ7.70–7.28(m,17H),6.97(d,J＝7.9Hz, 2H),5.23(dd,J＝44.0,12.3Hz,2H),5.00(d,J＝11.4Hz,1H),4.86(d,J＝11.4Hz,1H),4.75(q,J＝12.0Hz,2H),4.68(d,J＝0.9Hz,1H),4.45(td,J ＝9.5,2.5Hz,1H),4.10(t,J＝6.4Hz,1H),3.76(d,J＝9.6Hz,1H),3.58– 3.41(m,1H),3.08(d,J＝2.5Hz,1H),2.30(s,3H).
EXAMPLE 2 Synthesis of Compound II-1
In the first step, compound I-1 (15.0 g,26.3 mmol) was weighed into a 1000mL eggplant-type bottle, 400mL of anhydrous methylene chloride was added, the solution became reddish brown, levOH (7.6g,65.8 mmol,2.5eq), DIC (8.3 g,10.2mL,65.8mmol,2.5 eq) and DMAP (8.1 g,65.8mmol,2.5 eq) were added, and the solution was stirred at room temperature for 3 hours to become brown and turbid. TLC (EA/hex=1/2) indicated complete conversion of starting material. Saturated brine (500 mL) was added, the extract was separated, and the organic phase was concentrated under reduced pressure to give the crude product compound D-1 which was used directly in the next step.
The second step, crude compound D-1 was dissolved in 320mL of acetone/water (v/v=15/1), NBS (16.8 g,4 eq) was added as a pale yellow solution, and after several minutes turned to a reddish brown color, and stirred at room temperature for 1 hour, the solution turned pale yellow. TLC (EA/hex=1/2) indicated complete conversion of starting material. The reaction was quenched with saturated Na 2S2O3 solution (10 mL), extracted with dichloromethane (500 mL), the organic layer was washed once with saturated brine, and the solvent was removed by concentration under reduced pressure to give Compound E-1 as a yellow oil which was used directly in the next reaction.
In a third step, crude compound E-1 from the previous step was dissolved in 90mL of anhydrous dichloromethane, CNCCl 3 (6.3 g,4.3mL,5 eq) and DBU (663 mg,0.7mL,4.4mmol,0.5 eq) were added and the solution was dark brown and stirred under ice bath for 3 hours. TLC (EA/hex=1/2) indicated complete conversion of starting material. The reaction solution was concentrated under reduced pressure, and purified by column chromatography, eluting solution ratio (EA/hex=1/6-1/1) to give compound II-1 (13.5 g,19.2 mmol) as a pale yellow oil in 73% yield (based on compound I-1). The nuclear magnetic data are shown below:
1H NMR(400MHz,CDCl3)δ7.43–7.16(m,15H),6.53(d,J＝3.3 Hz,1H),5.60(t,J＝7.5Hz,1H),5.12(t,J＝12.9Hz,1H),5.03(d,J＝12.2Hz,1H),4.88(d,J＝46.7Hz,2H),4.65(ddd,J＝34.3,16.0,6.9Hz,1H), 4.51(d,J＝7.6Hz,1H),4.49–4.38(m,1H),3.89(dd,J＝7.8,2.9Hz,1H),3.85–3.76(m,1H),2.72–2.44(m,3H),2.39(d,J＝7.2Hz,1H),2.15(d,J ＝11.7Hz,3H).
EXAMPLE 3 Synthesis of Compound III-1
Compound D-1 (300 mg,0.45 mmol) was weighed into 20mL of anhydrous DCM and TTBP (334.8 mg,1.35mmol,3 eq) was added under nitrogen protection, diphenyl sulfoxide (109 mg,0.54mmol, 1.2 eq), dried 4 angstrom molecular sieve (500 mg) and the solution stirred at-78℃for 10 min. Tf 2 O (141 mg,0.5mmol,1.1 eq) was added. The solution was stirred for 10 min, benzyl alcohol (54mg,0.5 mmol,1.1eq) was added and reacted at-78 ℃ for 1 hour, TLC (EA/hex=1/2) indicated complete conversion of starting material. Saturated sodium bicarbonate was added to adjust the pH to neutral, the molecular sieve was removed, and the organic phase was concentrated under reduced pressure to give crude compound F-1, which was redissolved in 20mL DCM/pyridine (v/v=4/1), hydrazine acetate (180 mg,1.95mmol,4.33 eq) was added and stirred at room temperature for 2 hours. TLC (EA/hex=1/2) indicated the disappearance of starting material. The reaction was quenched by the addition of acetone, diluted with dichloromethane, further diluted with hydrochloric acid to adjust the pH to neutrality, washed once with saturated brine, dried over anhydrous sodium sulfate, filtered, the organic phase concentrated, purified by column chromatography, and the eluent ratio (EA/Hex=1/4-1/1) to give compound III-1 (224 mg,0.41 mmol) as a colorless oil in 90% yield (based on compound D-1). The nuclear magnetic data are shown below:
1H NMR(600MHz,CDCl3)δ7.49–7.06(m,20H),5.24(q,J＝12.3 Hz,2H),5.03(d,J＝1.6Hz,1H),4.74(d,J＝11.9Hz,1H),4.70–4.54(m,3H),4.50(d,J＝11.9Hz,1H),4.35(td,J＝9.2,2.4Hz,1H),4.20(d,J＝9.3 Hz,1H),3.80(dd,J＝9.2,3.0Hz,1H),3.78–3.71(m,1H),2.82(d,J＝2.4 Hz,1H).
EXAMPLE 4 Synthesis of Compound IV-1
Compound II-1 (2.0 g,2.84 mmol) and compound III-1 (1.7 g,3.12mmol, 1.1 eq) were weighed out and dissolved in 80mL of anhydrous DCM, the solution was reddish brown, dry 4 angstrom molecular sieve (1.8 g) was added, TMSOTF (126 mg,0.57mmol, 0.2 eq) was added after stirring at-40℃for 10min, and the reaction was stirred for 1 hour under N 2 protection, TLC (EA/Hex=1/2) indicated the disappearance of compound II-1. Triethylamine was added to adjust pH to neutrality, molecular sieves were removed, the organic phase was concentrated under reduced pressure, redissolved in 20mL DCM/pyridine (v/v=4/1), hydrazine acetate (1130mg,12.3mmol,4.33 eq) was added and stirred at room temperature for 5 hours. TLC (EA/hex=1/2) indicated the disappearance of starting material. The reaction was quenched with acetone, diluted with dichloromethane, further diluted with hydrochloric acid to adjust the pH to neutrality, washed once with saturated brine, dried over anhydrous sodium sulfate, filtered, and the organic phase concentrated, purified by column chromatography, and eluted in the ratio (EA/Hex=1/8-1/1) to give compound IV-1 (1813 mg, 1.8 mmol) as a pale yellow oil in 64% yield. The nuclear magnetic data are shown below:
1H NMR(600MHz,CDCl3)δ7.35–6.92(m,35H),5.19(s,1H),5.08 (d,J＝12.2Hz,1H),5.00(d,J＝12.2Hz,1H),4.94(d,J＝12.2Hz,1H),4.80(dd,J＝27.2,12.1Hz,2H),4.71(d,J＝12.2Hz,1H),4.57(dd,J＝12.1, 4.8Hz,2H),4.52–4.35(m,8H),4.35–4.28(m,1H),4.18(t,J＝9.5Hz, 1H),4.03–3.93(m,1H),3.72(t,J＝4.2Hz,1H),3.64–3.56(m,2H),3.15(dd,J＝9.5,2.8Hz,1H),2.94(s,1H).
EXAMPLE 5 Synthesis of beta-D- (1, 4) -mannuronic acid disaccharide (Compound IX-1)
Compound IV-1 (500 mg,0.5 mmol) was dissolved in 22mL THF/H 2 O/t-BuOH (v/v/v=1/1/0.2), palladium on charcoal (palladium content 10%) (50 mg) was added and the reaction was stirred under hydrogen for 48 hours at 25 ℃ and TLC (EA/hex=1/2) indicated the disappearance of starting material, palladium on charcoal was filtered off, the three palladium on charcoal layers were washed with water (50 mL x 3), the aqueous phases were combined, extracted once with EA (100 mL), concentrated to 10mL under reduced pressure and freeze-dried to give compound IX-1 (160 mg, 0.4 mmol) as a white solid in 86% yield. The nuclear magnetic data are shown below:
1H NMR(600MHz,D2O)δ5.23–5.12(m,1H),4.75(d,J＝9.4Hz, 1H),4.67–4.57(m,1H),4.40(t,J＝6.8Hz,1H),4.08(dt,J＝45.1,20.4Hz,1H),4.02–3.85(m,2H),3.85–3.67(m,2H),3.67–3.48(m,1H).
13C NMR(151MHz,D2O)δ172.85,172.73,101.35,101.06,99.82, 95.47,94.08,93.28,92.97,79.52,77.87,76.14,75.36,75.22,72.32,72.27,71.82,71.16,70.11,69.96,69.84,69.80,69.75,69.64,69.59,69.53,69.43, 69.21,69.04,67.91,67.79,67.75,67.66.
EXAMPLE 6 Synthesis of Compound VI-1
Compound II-1 (2.0 g,2.84 mmol) and compound I-1 (1.78g,3.13mmol,1.1 eq) were weighed out and dissolved in 80mL of anhydrous DCM as a reddish brown color, dried 4 angstrom molecular sieve (2.0 g) was added, TMSOTF (126 mg,0.57mmol,0.2 eq) was added after stirring at-40℃for 10min, and stirring was continued for 1 hour under N 2 protection, and TLC (EA/Hex=1/2) indicated that compound II-1 was completely reacted. Saturated sodium bicarbonate was added to adjust pH to neutrality, molecular sieves were removed by filtration, extraction, drying, concentration, column chromatography separation and purification, eluent ratio (EA/Hex=1/8-1/1) to give compound VI-1 (2.7 g,2.42 mmol) as a pale yellow solid in 86% yield. The nuclear magnetic data are shown below:
1H NMR(600MHz,CDCl3)δ7.39–7.15(m,34H),6.90(d,J＝8.0Hz, 2H),5.68(d,J＝6.8Hz,1H),5.56–5.46(m,1H),5.13–5.02(m,2H),4.92 (dd,J＝36.4,12.2Hz,2H),4.75–4.53(m,3H),4.53–4.38(m,7H),4.38–4.26(m,1H),4.16(s,1H),3.83(dt,J＝9.6,3.2Hz,2H),3.73(dd,J＝8.1, 2.7Hz,1H),3.40(dd,J＝9.6,2.8Hz,1H),2.57(dt,J＝19.8,7.8Hz,1H),2.52–2.37(m,2H),2.36–2.25(m,1H),2.22(s,3H),2.15–2.05(m,3H)
EXAMPLE 7 Synthesis of beta-D- (1, 4) -mannuronate tetrasaccharide (Compound IX-2)
In the first step, VI-1 (500 mg,0.45 mmol) was weighed into 20mL of anhydrous DCM, TTBP (334.8 mg,1.35mmol,3 eq) was added under nitrogen protection, diphenyl sulfoxide (109mg,0.54 mmol,1.2eq), dried 4 angstrom molecular sieve 500 mg) and the solution stirred at-78℃for 10 min. Tf 2 O (141 mg,0.5mmol,1.1 eq) was added. The solution was stirred for 10 min, compound IV-1 (500 mg,0.5mmol,1.1 eq) was added and the reaction was allowed to react at-78 ℃ for 1h, TLC (EA/hex=1/2) indicating complete conversion of starting material. Saturated sodium bicarbonate was added to adjust the pH to neutral, the molecular sieve was removed, the organic phase was concentrated under reduced pressure, redissolved in 20mL DCM/pyridine (v/v=4/1), hydrazine acetate (180 mg,1.95mmol,4.33eq) was added and stirred at room temperature for 2 hours. TLC (EA/hex=1/2) indicated the disappearance of starting material. The reaction was quenched by the addition of acetone, diluted with dichloromethane, further diluted with hydrochloric acid to adjust the pH to neutrality, washed once with saturated brine, dried over anhydrous sodium sulfate, filtered, the organic phase concentrated, purified by column chromatography, eluent ratio (EA/Hex=1/4-1/1) to give compound VIII-1 (766 mg,0.405 mmol) as a pale yellow solid in 90% yield (based on compound VI-1).
In a second step, compound VIII-1 (766 mg,0.405 mmol) was dissolved in 22mL of THF/H 2 O/t-BuOH (v/v/v=1/1/0.2), palladium on charcoal (palladium content 10%) (300 mg) was added, and the reaction was stirred under hydrogen for 48 hours at 25 ℃ C., TLC (EA/hex=1/2) indicated the disappearance of starting material, palladium on charcoal was filtered off, the three palladium on charcoal layers were washed with water (50 mL. Times.3), the aqueous phases were combined, extracted once with EA (100 mL), concentrated to 10mL under reduced pressure, and lyophilized to give compound IX-2 (263 mg,0.365 mmol) as a white solid in 90% yield.
1H NMR(600MHz,D2O)δ5.22(d,J＝4.4Hz,1H),4.98–4.80(m, 2H),4.82–4.76(m,2H),4.46(d,J＝6.6Hz,1H),4.17(t,J＝6.9Hz,1H), 4.13–3.87(m,8H),3.87–3.65(m,3H),3.65–3.48(m,2H).
13C NMR(150MHz,D2O)δ172.68,172.11,171.66,100.40,100.37, 99.86,95.47,93.99,92.93,77.94,77.84,77.66,76.54,75.23,74.38,73.03,72.93,72.31,71.81,71.16,70.97,69.97,69.60,69.53,69.46,69.19,69.04, 67.63.
EXAMPLE 8 Synthesis of beta-D- (1, 4) -mannuronate trisaccharide (Compound IX-3)
In the first step, compound II-1 (2.0 g,2.84 mmol) and Compound IV-1 (3.12g,3.13 mmol,1.1eq) were weighed and dissolved in 100mL of anhydrous DCM, the solution was reddish brown, dried 4 angstrom molecular sieve (1.8 g) was added, TMSOTF (126 mg,0.57mmol,0.2 eq) was added after stirring at-40℃for 10min, and the reaction was stirred for 1 hour under N 2. TLC (EA/hex=1/2) indicated that compound II-1 disappeared. Triethylamine was added to adjust pH to neutrality, molecular sieves were removed, the organic phase was concentrated under reduced pressure, redissolved in 50mL DCM/pyridine (v/v=4/1), hydrazine acetate (1130mg,12.3 mmol,4.33eq) was added and stirred at room temperature for 5 hours. TLC (EA/hex=1/2) indicated the disappearance of starting material. The reaction was quenched by the addition of acetone, diluted with dichloromethane, further diluted with hydrochloric acid to adjust the pH to neutrality, washed once with saturated brine, dried over anhydrous sodium sulfate, filtered, the organic phase concentrated, purified by column chromatography, and the eluent ratio (EA/Hex=1/8-1/1) to give compound V-1 (2547 mg,1.76 mmol) as a pale yellow oil in 62% yield. The nuclear magnetic data are shown below:
1H NMR(600MHz,CDCl3)δ7.26(ddd,J＝48.8,27.9,19.6Hz,50H), 5.25(s,1H),5.14–4.97(m,4H),4.88(dd,J＝27.9,12.0Hz,3H),4.73(t,J＝11.9Hz,2H),4.62(ddd,J＝33.3,22.0,11.5Hz,6H),4.54–4.39(m,8H), 4.39–4.27(m,2H),4.17(t,J＝8.7Hz,1H),4.04(s,1H),3.79(d,J＝8.3Hz,1H),3.70(d,J＝14.7Hz,3H),3.48(d,J＝9.3Hz,1H),3.45–3.34(m,1H), 3.11(d,J＝8.3Hz,1H),2.82(s,1H).
in a second step, compound V-1 (500 mg,0.34 mmol) was dissolved in 20mL of THF/H 2 O/t-BuOH (V/V/v=1/1/0.2), palladium on charcoal (palladium content 10%) (50 mg) was added, the reaction was stirred under hydrogen for 48 hours at 25 ℃ C., TLC (EA/Hex=1/2) indicated the disappearance of the starting material, palladium on charcoal was filtered off, the three palladium on charcoal layers were washed with water (50 mL. Times.3), the aqueous phases were combined, extracted once with EA (100 mL), concentrated to 10mL under reduced pressure, and lyophilized to give compound IX-3 (167 mg,0.31 mmol) as a white solid in 90% yield. The nuclear magnetic data are shown below:
1H NMR(600MHz,D2O)δ5.17(d,J＝4.3Hz,1H),4.77(s,1H),4.41 (d,J＝6.6Hz,1H),4.11(d,J＝6.7Hz,1H),4.05–3.94(m,3H),3.94–3.89(m,2H),3.88(d,J＝9.9Hz,1H),3.82–3.77(m,1H),3.77–3.65(m,3H),3.58(dd,J＝9.5,3.0Hz,1H).
13C NMR(151MHz,D2O)δ185.70,172.66,172.09,171.67,100.34, 99.85,93.97,92.93,77.93,77.84,77.73,77.64,74.36,73.03,72.30,71.79,71.12,70.95,70.56,70.08,69.98,69.55,69.48,69.18,69.02,67.72,67.61.
EXAMPLE 9 Synthesis of beta-D- (1, 4) -mannuronic acid pentasaccharide (Compound IX-4)
In the first step, VI-1 (500 mg,0.45 mmol) was weighed and dissolved in 20mL of anhydrous DCM, TTBP (334.8 mg,1.35mmol,3 eq) was added under nitrogen protection, diphenyl sulfoxide (109mg,0.54 mmol,1.2eq), dried 4 angstrom molecular sieve 500 mg), the solution was stirred at-78℃for 10min, tf 2 O (141 mg,0.5mmol,1.1 eq) was added, the solution was stirred for 10min, compound V-1 (323 mg,0.5mmol,1.1 eq) was added, the reaction was allowed to react at-78℃for 1 hour, and TLC (EA/Hex=1/2) indicated complete conversion of starting material. Saturated sodium bicarbonate was added to adjust the pH to neutral, the molecular sieve was removed, the organic phase was concentrated under reduced pressure, redissolved in 20mL of DCM/pyridine (v/v=4/1), hydrazine acetate (180 mg,1.95mmol,4.33 eq) was added and stirred at room temperature for 2 hours. TLC (EA/hex=1/2) indicated the disappearance of starting material. The reaction was quenched by the addition of acetone, diluted with dichloromethane, further diluted with hydrochloric acid to adjust the pH to neutrality, washed once with saturated brine, dried over anhydrous sodium sulfate, filtered, the organic phase concentrated, purified by column chromatography, eluent ratio (EA/Hex=1/4-1/1) to give compound VIII-2 (935 mg,0.40 mmol) as a pale yellow solid in 88% yield (based on compound VI-1).
In a second step, compound VIII-2 (935 mg,0.40 mmol) was dissolved in 22mL of THF/H 2 O/t-BuOH (v/v/v=1/1/0.2), palladium on charcoal (palladium content 10%) (300 mg) was added, the reaction was stirred under hydrogen for 48 hours at 25 ℃ C., TLC (EA/hex=1/2) indicated the disappearance of starting material, palladium on charcoal was filtered off, the three palladium on charcoal layers were washed with water (50 mL. Times.3), the aqueous phases were combined, extracted once with EA (100 mL), concentrated to 10mL under reduced pressure, and lyophilized to give compound IX-4 (323 mg,0.36 mmol) as a white solid in 90% yield. The nuclear magnetic data are shown below:
1H NMR(600MHz,D2O)δ5.17(s,1H),4.86(s,1H),4.63–4.51(m, 3H),4.29(d,J＝5.8Hz,1H),4.05(s,1H),3.97(s,3H),3.91(t,J＝10.4Hz,2H),3.84(d,J＝9.3Hz,6H),3.76(dd,J＝14.9,7.5Hz,2H),3.72(d,J＝18.2Hz,3H),3.58(d,J＝7.0Hz,1H),3.53(s,1H).
13C NMR(151MHz,D2O)δ174.35,174.12,173.65,173.37,172.69, 100.23,100.15,99.78,97.86,93.81,93.18,78.07,78.00,77.86,77.79,74.50,72.39,71.24,70.38,70.15,69.80,69.71,69.51,69.01,67.99,67.45,61.48.
EXAMPLE 10 Synthesis of beta-D- (1, 4) -mannuronate heptasaccharide (Compound IX-5)
In the first step, compound VI-1 (500 mg,0.45 mmol) was weighed into 20mL of DCM/pyridine (v/v=4/1), hydrazine acetate (180 mg,1.95mmol,4.33 eq) was added and stirred at room temperature for 2 hours. TLC (EA/hex=1/2) indicated the disappearance of starting material. The reaction was quenched by the addition of acetone, diluted with dichloromethane, then diluted hydrochloric acid to adjust the pH to neutrality, washed once with saturated brine, dried over anhydrous sodium sulfate, filtered, the organic phase concentrated, dried 4 angstrom molecular sieve (2.0 g) was added, redissolved in 20mL anhydrous DCM, compound II-1 (317 m g,0.45 mmol) was added, the solution was reddish brown, the temperature was controlled below-40℃under protection of N 2, TMSOTF (20 mg,0.09mmol,0.2 eq) was added after stirring for 10min, and stirring was carried out for 1 hour. TLC (EA/hex=1/2) indicated that compound II-1 was completely reacted. Saturated sodium bicarbonate was added to adjust the pH to neutral, molecular sieves were removed by filtration, dried and concentrated by extraction, column chromatography over silica gel, eluent ratio (EA/Hex=1/8-1/1) to give compound VII-1 (560 mg, 0.36 mmol) as a pale yellow solid in 80% yield (based on compound VI-1).
In a second step VII-1 (500 mg,0.32 mmol) was weighed and dissolved in 20mL of anhydrous DCM, TTBP (238 mg,0.96mmol,3 eq) was added under nitrogen protection, diphenyl sulfoxide (78 mg,0.38mmol, 1.2 eq), dried 4 angstrom molecular sieve (500 mg), the solution was stirred at-78℃for 10 min, tf 2 O (100 mg,0.35mmol,1.1 eq) was added, the solution was stirred for 10 min, compound VIII-1 (663 mg,0.35mmol,1.1 eq) was added and the reaction was carried out at-78℃for 1 h, TLC (EA/Hex=1/2) indicated complete conversion of starting material. Saturated sodium bicarbonate was added to adjust the pH to neutral, the molecular sieve was removed, the organic phase was concentrated under reduced pressure, redissolved in 20mL of DCM/pyridine (v/v=4/1), hydrazine acetate (128 mg,1.39mmol,4.33 eq) was added and stirred at room temperature for 2 hours. TLC (EA/hex=1/2) indicated the disappearance of starting material. The reaction was quenched by the addition of acetone, diluted with dichloromethane, further diluted with hydrochloric acid to adjust the pH to neutrality, washed once with saturated brine, dried over anhydrous sodium sulfate, filtered, the organic phase concentrated, purified by column chromatography, eluent ratio (EA/Hex=1/4-1/1) to give compound VIII-3 (660 mg,0.27 mmol) as a pale yellow solid in 85% yield (based on compound VII-1).
In a third step, compound VIII-3 (660 mg,0.27 mmol) was dissolved in 22mL of THF/H 2 O/t-BuOH (v/v/v=1/1/0.2), palladium on charcoal (10% palladium content) was added (300 mg), the reaction was stirred under hydrogen for 48 hours at 25 ℃ and TLC (EA/hex=1/2) indicated the disappearance of starting material, palladium on charcoal was filtered off, the three palladium on charcoal layers were washed with water (50 mL. Times.3), the aqueous phases were combined, extracted once with EA (100 mL), concentrated to 10mL under reduced pressure, and lyophilized to give compound IX-5 (300 mg,0.24 mmol) as a white solid in 89% yield. The nuclear magnetic data are shown below:
1H NMR(600MHz,D2O)δ5.96(d,J＝3.9Hz,1H),5.15(s,1H),4.84 (s,2H),4.65(d,J＝3.9Hz,3H),4.60(s,3H),4.16(s,1H),4.10–4.01(m,1H),3.96(s,3H),3.91(s,2H),3.84(d,J＝16.4Hz,5H),3.70(s,6H),3.66 (d,J＝6.7Hz,4H),3.56(dd,J＝12.2,6.7Hz,3H).
13C NMR(151MHz,D2O)δ174.37,174.05,174.02,174.01,173.94, 173.84,173.60,100.23,100.15,99.78,97.86,93.81,93.19,78.08,78.00,77.87,77.79,74.64,72.39,71.25,70.38,70.16,69.80,69.71,69.51,69.01, 68.00,67.45,61.49.
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| PCT/CN2021/094459 WO2021233314A1 (en) | 2020-05-19 | 2021-05-18 | METHODS FOR PREPARING β-D-(1,4)-MANNURONATE OLIGOSACCHARIDE AND INTERMEDIATE THEREOF |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN100508985C (en) * | 2004-03-24 | 2009-07-08 | 中国海洋大学 | Algin oligose and derivative thereof and producing method and use thereof |
| WO2012138698A1 (en) * | 2011-04-08 | 2012-10-11 | Ancora Pharmaceuticals Inc. | Synthesis of beta-mannuronic acid oligosaccharides |
| WO2020070258A1 (en) * | 2018-10-03 | 2020-04-09 | Carmeda Ab | Immobilised biological entities |
| WO2021233314A1 (en) * | 2020-05-19 | 2021-11-25 | 绿谷(上海)医药科技有限公司 | METHODS FOR PREPARING β-D-(1,4)-MANNURONATE OLIGOSACCHARIDE AND INTERMEDIATE THEREOF |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100508985C (en) * | 2004-03-24 | 2009-07-08 | 中国海洋大学 | Algin oligose and derivative thereof and producing method and use thereof |
| WO2012138698A1 (en) * | 2011-04-08 | 2012-10-11 | Ancora Pharmaceuticals Inc. | Synthesis of beta-mannuronic acid oligosaccharides |
| WO2020070258A1 (en) * | 2018-10-03 | 2020-04-09 | Carmeda Ab | Immobilised biological entities |
| WO2021233314A1 (en) * | 2020-05-19 | 2021-11-25 | 绿谷(上海)医药科技有限公司 | METHODS FOR PREPARING β-D-(1,4)-MANNURONATE OLIGOSACCHARIDE AND INTERMEDIATE THEREOF |
Non-Patent Citations (8)
| Title |
|---|
| Automated Solid-Phase Synthesis of β-Mannuronic Acid Alginates;Marthe T. C. Walvoort等;《Angewandte Chemie》;20120214;第51卷;4393-4396 * |
| B. Schumann等.Synthesis of conjugation-ready zwitterionic oligosaccharides by chemoselective thioglycoside activation.《Chemical Science》.2014,(第2014年第5期),1992-2002. * |
| Eleni Dimitriou等.Exploring a glycosylation methodology for the synthesis of hydroxamate-modified alginate building blocks.《Organic & Biomolecular Chemistry》.2019,第17卷(第42期),9321-9335. * |
| Exploring a glycosylation methodology for the synthesis of hydroxamate-modified alginate building blocks;Eleni Dimitriou等;《Organic & Biomolecular Chemistry》;20191004;第17卷(第42期);9321-9335 * |
| Jeroen D. C. Codeé.The Stereodirecting Effect of the Glycosyl C5-Carboxylate Ester: Stereoselective Synthesis of β-Mannuronic Acid Alginates.《The Journal of Organic Chemistry》.2008,第74卷(第1期),38-47. * |
| Synthesis of conjugation-ready zwitterionic oligosaccharides by chemoselective thioglycoside activation;B. Schumann等;《Chemical Science》;20140311(第2014年第5期);1992-2002 * |
| Synthesis of the two monomethyl esters of the disaccharide 4-O-α-d-galacturonosyl-d-galacturonic acid and of precursors for the preparation of higher oligomers methyl uronated in definite sequences;Didier Magaud等;《Carbohydrate Research》;19981231;第314卷;189-199 * |
| The Stereodirecting Effect of the Glycosyl C5-Carboxylate Ester: Stereoselective Synthesis of β-Mannuronic Acid Alginates;Jeroen D. C. Codeé;《The Journal of Organic Chemistry》;20081126;第74卷(第1期);38-47 * |
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