A total synthesis of rhizoxin D (1b), a 16-membered antitumoral macrolide, is reported. The strategy relies on the application of a Brown allylation reaction for the C15 and C16 asymmetric centres control. Installation of the C17 hydroxyl function with concomitant building of the (E)-C18-C19 double bond was effected by a diastereoselective addition of vinyllithium derivative 15 to aldehyde 10. The terminal enone group was then introduced to achieve the preparation of C11-C20 segment 23. A Heck coupling reaction between C11-C20 fragment 23 and C3-C10 segment 24 (previously prepared in our laboratory) was performed with success to deliver the C3-C20 fragment 25. The total synthesis of rhizoxin D (1b) was achieved after transformation of 25 into the macrolactone 28, and coupling the C21-C28 side chain using a Wittig-Wadsworth-Emmons reaction.
报告了一种 16 元抗肿瘤
大环内酯类药物 rhizoxin D (1b) 的全合成方法。该策略依靠布朗烯丙基化反应来控制 C15 和 C16 不对称中心。通过
乙烯锂衍
生物 15 与醛 10 的非对映选择性加成,实现了 C17 羟基官能团的安装以及 (E)-C18-C19 双键的建立。然后引入末端烯酮基团,制备出 C11-C20 段 23。C11-C20 片段 23 与 C3-C10 片段 24(之前在我们实验室制备)之间的赫克偶联反应成功地得到了 C3-C20 片段 25。在将 25 转化为大内酯 28 并使用 Wittig-Wadsworth-Emmons 反应偶联 C21-C28 侧链之后,就完成了
根皮素 D(1b)的全合成。