Chemoselective glycosylations of sterically hindered glycosyl acceptors

Unexpected intermolecular aglycon transfer in chemoselective glycosylations between activated thioglycosyl donors and deactivated thioglycosyl acceptors could be avoided by employing a glycosyl acceptor that has a bulky anomeric dicyclohexylmethanethio group. The methodology was applied to the synthesis of a protected fragment of an oligosaccharide released from the jelly coat glycoprotein of X. leavis.