SYNTHESIS OF METHYL 4-ACETAMIDO-N-ACETYL-4-DEOXY-ALPHA- AND BETA-4-EPI-NEURAMINIC ACIDS

摘要

Methyl 5-acetamido-7,8,9-tri-O-acetyl-4-azido-2,3,4,5-tetradeoxy-D-glycero-D-talo - nonulopyranosonate with N-bromosuccinimide in methanol gave methyl (methyl 5-acetamido-7,8,9-tri-O-acetyl-4-azido-3-bromo-3,4,5-trideoxy-alpha-D-ralo -nonulopyranosid) and methyl (methyl 5-acetamido-7,8,9-tri-O-acetyl-4-azido-3-bromo-3,4,5-trideoxy-beta-D-glyce ro-D-talo-nonulopyranosid)onate, which on reductive acetylation with H-2/Pd-C in acetic anhydride-ethyl acetate yielded the corresponding 4-acetamido analogues. Debromination with Bu(3)SnH/AIBN in toluene, followed by hydrolysis, gave methyl 4-acetamido-N-acetyl-4-deoxy-alpha-and beta-4-epi-neuraminic acids. [References: 36]