A first total synthesis of a novel sulfated ganglioside, 3′-O-sulfo-GM1b Original Research Article

A first total synthesis of a novel sulfated ganglioside, 3′-O-sulfo-GM1b, is described. The suitably protected gangliotriose (GgOSe3) derivative, 2-(trimethylsilyl)ethyl (2-acetamido-4,6-O-benzylidene-2-deoxy-β-d-galactopyranosyl)-(1→4)-(2,6-di-O-benzyl-3-O-p-methoxybenzyl-β-d-galactopyranosyl)-(1→4)-2,3,6-tri-O-benzyl-β-d-glucopyranoside was glycosylated with the α-NeuAc-(2→3)-galactose donor to give the protected GM1b oligosaccharide (95%). After proper manipulation of the protecting groups, the oligosaccharide was converted into the target ganglioside by the successive introduction of the ceramide and sulfo groups, followed by complete deprotection.