摘要:
Partially protected 2-(trimethylsilyl)ethyl deoxylactosides (deoxygenated in the 2-, 3-, and 6-positions of the galactose unit) were synthesized via various routes and glycosylated with 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 86-96% overall yield. Glycosylation of 3-(hexadecylsulfonyl)-2-[(hexadecylsulfonyl)methyl]propanol with the trisaccharidic trichloroacetimidates, in 37-68% yield, followed by removal of protecting groups, gave the title neoglycolipids.