Facile synthesis of 2-(β-C-glucopyranosyl)-β-amino acid: a new class of glycopeptide building block

A convenient preparation of both stereoisomers of a (2R)/(2S)-2-C-glycosylated β-amino acid is described. β-C-Glycoside was formed by the reaction of α-acetobromoglucose with carbanion of cyanoacetate. The steric bulk of the C-glycoside moiety does not hinder amino acid coupling, showing the utility of this carbohydrate-containing building block for glycopeptide synthesis.