SYNTHESIS OF ALIPHATIC O-DIMANNOSYL AMINO-ACID BUILDING-BLOCKS FOR SOLID-PHASE ASSEMBLY OF GLYCOPEPTIDE LIBRARIES

The preparation of alpha(1,2)-, alpha(1,3)- and alpha(1,6)-linked mann ose disaccharides is described. The protected alpha-D-Man(1-->3)-D-Man disaccharide was synthesized using the trichloroacetimidate method, w hile the Konigs-Knorr procedure was employed in the preparation of the 1-->2- and 1-->6-linked disaccharides. Glycosylation of N-alpha-Fmoc- Ser-OPfp, N-alpha-Fmoc-Thr-OPfp and N-alpha-Fmoc-Hyp-OPfp with the dim annosyl bromides afforded the activated building blacks, in moderate t o high yield, for direct use in solid-phase synthesis of glycopeptide libraries.