N,N-DIACETYL-GLUCOSAMINE AND N,N-DIACETYL-GALACTOSAMINE DERIVATIVES AS GLYCOSYL DONORS

N-Acetyl-glucosamine and N-acetyl-galactosamine were converted into the O-acetyl protected 1-methylthio-derivatives 1A,B which were then transformed into N,N-diacetyl derivatives 2A and 2B, respectively. Activation of 2A,B with DMTST afforded good glycosyl donors for the generation of P-linkages: thus, reaction with accepters 3a,b gave oligosaccharides 4Aa and 4Ba in high and 4Ab and 4Bb in good yields. Mono-N-deacetylation could be performed with NaOMe/MeOH in quantitative yield, thus concluding a convenient procedure for the formation of beta-linked GlcNAc and GalNAc glycosides.