An efficient short-step total synthesis of ganglioside GM3: Effective usage of the neighbouring group participation strategy

Article abstract of DOI:10.1016/0008-6215(96)00015-8

We have developed an efficient methodology for highly stereoselective sialylation using 3-position substituted sialic acids and have prepared 2a having a 3β-phenylthio group as a sialic donor. Glycosylation of suitably protected lactoside 3 with 2a gave only the α-sialyl trisaccharide 16 in good yield. Condensation of the azidosphingosine 4 with the acetate 17 using promotors, DMTST or NIS-TfOH, afforded the glycolipid 18, which was directly transformed to 20 by reduction with Bu₃P and subsequent acylation with octadecanoic acid in the presence of WSC. Removal of the protecting groups generated ganglioside CM₃ (1).