stereocontrol. The yield for the 29-step longest linear sequence from Roche ester was 1.53 %. The final key steps to this unnatural product were the vinylzincate C10-C26 addition to aldehyde C1-C9 (leading surprisingly to a complete stereoselectivity for the 9R-epimer), followed by Yamaguchi macrolactonization and global deprotection.
(+)-9-epi-dictyostatin (1b) 是抗有丝分裂海洋海绵衍生的大环内
酯 (-)-dictyostatin (1a) 的非对映异构体,通过创建 11 个立体中心和 4 个立体双核实现了全合成结合高
水平的立体控制。来自罗氏
酯的 29 步最长线性序列的产率为 1.53%。这种非
天然产物的最后关键步骤是将
乙烯基锌酸 C10-C26 添加到醛 C1-C9(令人惊讶地导致 9R 差向异构体的完全立体选择性),然后是 Yamaguchi 大环内
酯化和全局
脱保护。