Synthesis of (Z)-3-Deoxy-3-(1,2,3,6-Tetradeoxy-3,6-Imino-L-Arabino-Hexitol-1-C-Ylidene)-D-Xylo-Hexose Derivatives. First Examples Of Homo-(1→3)-C-Linked Iminodisaccharides.
摘要:
Cross-aldolisation of 3,6-[(tert-butoxy)carbonyl]imino-2,3,6-trideoxy-4,5-O- isopropylidene-L-arabino-hexose (10) with 1,6-anhydro-2-O-benzyl-3-deoxy-beta-D-erythro-hexopyrano-4-ulose (6) generates, after water elimination, a single enone II that is reduced selectively into an allylic alcohol 12, deprotection of which affords methyl (Z)-3-deoxy-3-(1,2,3,6-tetradeoxy-3,6-imino-L-arabino-hexitol-1-C-ylidene)-beta-D-xylo-hexofuranoside (1) and (Z)-1,6-anhydro-3-deoxy-3-(1,2,3,6-tetradeoxy-3,6-imino-L-arabino-hexitol-1 -C-ylidene)-beta-D-xylo-hexopyranose (14).
Hydroxylated pyrrolidines. Synthesis of 1,4-dideoxy-1,4-imino-L-lyxitol, 1,4,5-trideoxy-1,4-imino-D- and -L-lyxo-hexitol, 2,3,6-trideoxy-3,6-imino-D-glycero-L-altro- and -D-glycero-L-galacto-octitols, and of a chiral potential precursor of carbapenem systems
摘要:
Enantiospecific syntheses are reported for the title pyrrolidines, from carbohydrate precursors. An intermediate in one of the routes, ethyl 2,3,6-trideoxy-3,6-imino-4,5:7,8-di-O-isopropylidene-D-glycero-L-altro-octonate (23), could be converted in two steps into a beta-lactam.