Synthetic Studies of Rifamycins. VIII. An Improved Practical Synthesis of the Ansa-chain Compounds for the Rifamycin W Synthesis
作者:Masaya Nakata、Kazunobu Toshima、Toshiyuki Kai、Mitsuhiro Kinoshita
DOI:10.1246/bcsj.58.3457
日期:1985.12
The improved practical synthesis of 6,8,10-tri-O-acetyl-3-C-(acetoxymethyl)-3,5,7,9,11-pentadeoxy-1,2-O-isopropylidene-5,7,9,11-tetra-C-methyl-L-erythro-D-altro-β-L-talo-dodecodialdofuranose-(1,4) 12-(diethyl acetal) (3), a useful synthetic segment for the rifamycin W ansa-chain, is described. The key intermediate, 3-O-benzyl-2,4,7-trideoxy-5,6-O-isopropylidene-2,4-di-C-methyl-aldehydo-D-allo-heptose
6,8,10-tri-O-acetyl-3-C-(acetoxymethyl)-3,5,7,9,11-pentadeoxy-1,2-O-isopropylidene-5,7,9的改进实用合成,11-四-C-甲基-L-赤型-D-altro-β-L-talo-dodecodialdofuranose-(1,4) 12-(diethyl acetal) (3),利福霉素W ansa的有用合成片段链,进行了描述。关键中间体 3-O-benzyl-2,4,7-trideoxy-5,6-O-isopropylidene-2,4-di-C-methyl-aldehydo-D-allo-heptose (22),合成于甲基 4,6-O-benzylidene-3-deoxy-3-C-methyl-α-D-altropyranoside (8) 在 15 个步骤中的产率为 29.4%。22 与由丁基锂和 3