Intermolecular aglycon transfer of ethyl thioglycosides can be prevented by judicious choice of protecting groups

Abstract

Unexpected intermolecular aglycon transfer occurred in chemoselective glycosylations using glycosyl fluorides or trichloroacetimidates as glycosyl donors and partially protected thioglycosides as glycosyl acceptors. It is shown that this problem can be addressed by fine-tuning of the reactivity of the anomeric thioalkyl moiety and hydroxyl of the acceptor.