Branched-chain sugars. Part XIV. Reactions of some glycosulose derivatives with diazomethane: ring expansion of glycosulose derivatives

Abstract

Epoxidation of methyl 4,6-O-benzylidene-2-deoxy-α-D-erythro-hexopyranosid-3-ulose (1) and of 5-O-benzoyl-1,2-O-isopropylidene-α-D-erythro-pentofuranos-3-ulose (12) by treatment with diazomethane in methanol–ether has been shown to be accompanied by ring expansion (methylene insertion). The structures and configurations of the products have been established. Some aspects of the stereochemical course of the reactions are discussed.