SYNTHESIS OF GLYCOPEPTIDES OF THE MUCIN TYPE CONTAINING A β-D-GlcpNAc-(1->3)-D-GalpNAc UNIT

Article abstract of DOI:10.1016/0008-6215(89)85105-5

Mucin-type O-glycopeptides containing the β-D-GlcpNAc-(1->3)-D-GalpNAc core unit were synthesised from 2-azido-2-deoxy-D-glucose, 2-azido-2-deoxy-D-galactose, 2-azido-2-deoxylactose, and L-serine precursors, using the trichloroacetimidate method.Thus, β-D-GlcpNAc-(1->3)-α-D-GalpNAc-(1->3)-Ser (1) and a derivative of β-D-Galp-(1->4)-β-D-GlcpNAc-(1->6)-<β-D-GlcpNAc-(1->3)>-α-D-GalpNAc-(1->3)-Ser (2) were obtained.A precursor of 1 having HO-4,6 of the 2-azido-2-deoxy-D-galactose residue unsubstituted was a valuable intermediate for the synthesis of 2 due to regioselective glycosylation at O-6.Regioselectivity in this reaction was not observed for precursors having a tert-butyldimethylsilyl group at O-1 instead of a protected L-serine moiety.