title: Application of the trichloroacetimidate method to the synthesis of glycopeptides of the mucin type containing a beta-D-Galp-(1----3)-D-GalpNAc unit.
abstract: Mucin-type O-glycopeptides containing the beta-D-Galp-(1----3)-D-GalpNAc disaccharide core unit, which is also the T-antigenic determinant, were synthesized from D-galactose, 2-azido-2-deoxy-D-galactose, 2-azido-2-deoxylactose, and L-serine precursors by applying the trichloroacetimidate method. Thus, beta-D-Galp-(1----3)-alpha-D-GalpNAc-(1----3)-Ser (1) and beta-D-Galp-(1----4)-beta-D-GlcpNAac-(1----6)-[beta-D-Galp-(1----3 )]-alpha-D-GalpNAc-(1----3)-Ser (2) were obtained. A protected precursor of 2 having free OH groups at C-4 and C-6 of the inner sugar unit is a valuable intermediate for the synthesis of further O-glycopeptides of this core-unit type.
mesh_terms: D000116:Acetylgalactosamine; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005688:Galactosamine / Q000031:analogs & derivatives; D005690:Galactose; D006020:Glycopeptides / Q000138:chemical synthesis*; D007096:Imidoesters; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009077:Mucins / Q000138:chemical synthesis*; D009904:Optical Rotation
chemical_list: D006020:Glycopeptides; D007096:Imidoesters; D007202:Indicators and Reagents; D009077:Mucins; D005688:Galactosamine; D000116:Acetylgalactosamine; D005690:Galactose