O-(5-Acetamido-4,7,8,9-tetra-O-acetyl-3-thiophenyl-alpha-neuraminosyl Methyl Ester)-2-alpha-3-O-(6-O-benzyl-beta-D-galactopyranosyl)-1-beta-4-O-[6-deoxy-2,3,4-tri-O-benzyl-alpha-L-galactopyranosyl-(1-alpha-3)]-2-(acetylamino)-2-deoxy-1,6-di-O-benzyl-alpha