A Total Synthesis of the Methyl Glycoside of Ganglioside GM1

Abstract
The total synthesis of the methyl glycoside of GM1 (1b) has been accomplished. The key step in the synthesis involves the sulfonamidoglycosidation reaction, which is used to create a β-linkage leading to a GalNAc residue joined to the C4 hydroxyl group of a galactose unit of a C3 sialylated lactosyl moiety. The “proximal hydroxyl” directing effect, which has been postulated before, manifests in this context as well leading to the preponderant formation of the β-glycoside. Together with asialo GM1 and other substructures, the GM1 methyl glycoside has been submitted for biological assays as potential ligands for bacterial and viral infection sites.