An efficient synthesis of α-Neu5Ac-(2-3)-β-Gal-(1-4)-β-Glc-(1-1)-Cer (GM3) was described. A suitably protected lactoside diol was glycosylated with sialyl xanthate to give only the α-sialyl trisaccharide in good yield based on a highly stereo- and regioselective sialylation. Condensation of the azidosphingosine 8 with the imidate 7 using a promoter TMSOTf, afforded the glycolipid 9, which was directly transformed to 10 by reduction with Ph₃P and subsequent acylation with octadecanoic acid in the presence of EDC. After deprotection, the target GM3 was afforded, which can be applied to study of the tumor-vaccine. The structures of these compounds were fully confirmed by ¹H and ¹³C NMR, mass spectra (MS) and HRMS.

Key words: ganglioside, glycolipid, synthesis, GM3, tumor-vaccine