Acid Catalyzed Stereocontrolled Ferrier-Type Glycosylation Assisted By Perfluorinated Solvent

O-Glycosides are important biomolecules in the process of life activities,which are widely found in nature and are important in drug design due to their potential biological activities,and the synthesis of such compounds has received increasing attention in recent years.This paper presents the first application of perfluorinated solvents in the stereoselective formation of O-glycosides and S-glycosides by Ferrier rearrangement of acetyl-glycal.In this project,weak interactions between perfluorinated hexane and the substrate enhance the reaction rate and steric control.The initiation of the reaction requires only a minimal amount of H⁺from the cation exchange resin and mild conditions make the reaction broadly applicable to the substrate and 53 glycosides were synthesized using this method.The"green"nature of the reaction is characterized by low toxicity and easy recovery of the reaction medium,as well as simple product separation.The absolute structure of（α/β）glycoside derivatives were finally determined by ¹H NMR、¹³C NMR、NOESY、X-ray crystal diffraction.The ratio of epimerization（α/β）was determined detection,and the experimental results achieved the expected experimental purpose.The method has a singleα-O-glycoside selectivity for alcohol-based nucleophiles,when the nucleophiles are phenols,mercaptans and thiophenols,the method can also achieve good selectivity,up toα:β=11:1.The method realizes the selective control ofαandβto a certain extent.