Imposing the trans/gauche conformation on a sialic acid donor with a 5-N,7-O-oxazinanone group: effect on glycosylation stereoselectivity

A 5-N,7-O-oxazinanone derivative of a thiosialic acid ester has been synthesized and investigated for the effect of conformational restriction on glycosylation. The cyclic group is found to be powerfully disarming, but to have no beneficial effect on reaction stereoselectivity.