A reasonable synthesis design by strategically integrating functional group manipulation into the ring system construction resulted in a short, enantioselective, gram-scale total synthesis of (−)-zephyranthine. The concise route includes a catalytic Michael/Michael cascade for the asymmetric synthesis of a penta-substituted cyclohexane with three contiguous stereogenic centers, a remarkable 8-step
通过将官能团操作战略性地整合到环系统构建中,合理的合成设计导致 (-)-zephyranthine 的短、对映选择性、克级全合成。简洁的路线包括催化迈克尔/迈克尔级联,用于不对称合成具有三个连续立体中心的五取代环己烷,一个显着的 8 步一锅操作轻松组装 zephyranthine 四环骨架,双键的区域选择性构建在 C 环和不对称二羟基化。这种合成也很灵活,为各种环己胺稠合的三环或多环生物碱铺平了潜在的途径。
Asymmetric Total Syntheses of (−)-α-Lycorane, (−)-Zephyranthine, and Formal Synthesis of (+)-Clivonine
作者:Yong-Jian Chen、Sen-Lin Cai、Chuan-Chuan Wang、Jin-Duo Cheng、Søren Kramer、Xing-Wen Sun
DOI:10.1002/asia.201700555
日期:2017.6.19
An asymmetric route to (−)-α-lycorane and (−)-zephyranthine, and a formal totalsynthesis of (+)-clivonine were achieved. A pivotal intermediate, which serves as a potent precursor for the divergent syntheses of these natural products, was accessed by a diastereoselective Pd-catalyzed cinnamylation of an N-tert-butanesulfinyl imine.