Synthesis of Double-Chain Bis-Sulfone Neoglycolipids of the 2-, 3-, and 6-Deoxyglobotrioses

Partially protected 2-(trimethylsilyl)ethyl 2- and 3-deoxyglucosides and 6-deoxylactoside were synthesised via various routes and glycosylated with galabiosyl and galactosyl donors to give the corresponding deoxytrisaccharides. Removal of the protecting groups gave the 2-(trimethylsilyl)ethyl 2-, 3-, and 6-deoxyglobotriosides. Transformation of the protected trisaccharides into trichloroacetimidates, via the corresponding hemiacetals, proceeded in ∼80% overall yield. Glycosylation of 3-(hexadecylsulfonyl)-2-[(hexadecylsulfonyl)methyl]propanol with the trisaccharidic trichloroacetimidates, in 72−79% yield, followed by removal of protecting groups, gave the title neoglycolipids.