Reagent controlled stereoselective glycosylation

摘要

Provided are methods for the efficient stereoselective formation of glycosidic bonds, without recourse to prosthetic or directing groups.

主权项

1. A method of forming a glycosidic bond, comprising:
combining a first solvent, a reducing sugar, and a first strong Bronsted base, thereby forming a first reaction mixture; combining a sulfonylating agent and the first reaction mixture, thereby forming a glycosyl sulfonate; combining a second solvent, a glycosyl acceptor, and a second strong Bronsted base, thereby forming a second reaction mixture; and combining the glycosyl sulfonate and the second reaction mixture, thereby forming a glycosidic bond; wherein the reducing sugar is a pyranose; the sulfonylating agent is selected from the group consisting of tosyl 4-nitroimidazole, benzenesulfonyl 4-nitroimidazole, and p-toluenesulfonic anhydride; and the glycosidic bond is formed with greater than or equal to 90% stereoselectivity for a β linkage.