Method for synthesizing α-oxyglycosides stereoselectively using 3-O-quinaldine ester glycan donor

Abstract

A type based on 3 O A method for stereoselectively synthesizing α-oxyglycosides using a quinaldine ester glycan donor, comprising the steps of: using 3- O Quinaldine ester glucalose is a sugar donor, a catalyst, a ligand, triethylamine and a sugar acceptor and an organic solvent are added, and the reaction is stirred at 100-120 ° C. The reaction progress is monitored by TLC. After the reaction is carried out for 20-24 hours, the reaction is terminated to obtain an α-2,3-unsaturated oxygen glycoside. The technical solution of the present invention preferentially generates a product with a β configuration during the glycosidation reaction. Under the action of high temperature and palladium catalyst, the original β-glycosidic bond is broken and regenerated with an α configuration to obtain a thermodynamically stable α-2,3-unsaturated oxygen glycoside. The method has a wide range of substrate applicability, and the stereoselectivity of most substrates can reach at least α:β=10:1.

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