Synthesis of O-β-D-galactopyranosyl-(1→4)-O-2-acetamido-2-deoxy-β-D-glucopyranosyl-(1→3)-D-mannose, a postulated trisaccharide of human erythrocyte membrane sialoglycoprotein
developed for the synthesis of multiantennary N‐glycans of the complextype, which are commonly found on glycoproteins. The donor building blocks were laid out for the elongation of a core trisaccharide acceptor (β‐mannosyl chitobiose) conveniently protected with a single benzylidene moiety at the β‐mannoside. Through two consecutive regio‐ and stereoselective couplings the donors gave N‐glycans with three