DTBS EFFECT : THE UNIQUE STERICALLY DRIVEN DIRECTOR FOR α-GALACTOSYLATION

This review outlines the chemistry of 1,2-cis glycosylations and discusses the state-of-the-art methods, highlighting the DTBS(di-tert-butylsilylene)-directed α-galactosylation that was recently developed by our group. The key feature of our unique methodology includes extremely simple procedure, namely, the introduction of cyclic DTBS protecting group into 4- and 6-OH at galacto-type glycosyl donor. The power of the methodology was demonstrated by the syntheses of biologically relevant glycans including mucin-type glycosyl amino acids [α-O-GalNAc-Ser/Thr], α-galactosyl ceramides, globo-series glycolipids.