So far, several methods for the syntheses of α-GalCer [4] and iGb3 [5] have been reported; per-O-benzylated galactosyl donors with leaving groups such as fluoride, chloride, aryl sulfenyl, and trichloroacetimidate have been used for the formation of α-galactosyl linkages. However, α-selectivity and yield of glycosylation strictly depends on the structure of the glycosyl acceptor. In particular, galactosylation of the ceramide part is far from highly ...
