Regiospecific syntheses of N-acetyllactosamine derivatives and application toward a highly practical synthesis of Lewis X trisaccharide

Article abstract of DOI:10.1080/07328309908544034

An efficient methodology for regiospecific glycosylation was developed by using 6-O-tert-butyldiphenylsilyl N-acetylglucosamine derivatives 3 and 5 which bear two free hydroxyl groups as acceptors. The regiospecificity was attributed to the presence of the tert-butyldiphenylsilyl group at the O-6 position of the N-acetylglucosamine derivatives. Glycosylation of suitably protected galactoside donors 10-14 with acceptors 3 and 5 gave only β(1→4) linked disaccharides 15-19 in good yields. Fucosylation of disaccharide 18 led to Lewis X (Le^x) trisaccharide 21 in high yield.