Abstract The first total syntheses of disialoganglioside GD1α and its α2-6 positional isomer are described. Suitably protected pentasaccharide derivatives, derived from known pentasaccharide precursors, were selected as the glycosyl acceptors. Using our facile method of stereoselective α-glycosidation of sialic acid, these acceptors were coupled with methyl (methyl 5-acetamido-4,7,8,9-tetra- O -acetyl-3