Protecting-Group-Free Syntheses of <i>ent</i>-Kaurane Diterpenoids: [3+2+1] Cycloaddition/Cycloalkenylation Approach
作者:Jin Wang、Benke Hong、Dachao Hu、Yuichiro Kadonaga、Ruyao Tang、Xiaoguang Lei
DOI:10.1021/jacs.9b13722
日期:2020.2.5
[3+2+1] cycloaddition followed by a Pd-mediated 5-endo cycloalkenylation is shown to be a general and powerful approach for efficient construction of tetracyclic core structure of ent-kaurane diterpenoids. The utility of this strategy was further demonstrated by concise and protecting-group-free total syntheses of ent-1α-hydroxykauran-12-one, 12-oxo-9,11-dehydrokaurene and 12α-hydroxy-9,11-dehydrokaurene
Rh 催化的 [3+2+1] 环加成和 Pd 介导的 5-endo 环烯基化被证明是有效构建 ent-kaurane 二萜四环核心结构的通用且有效的方法。该策略的实用性通过 ent-1α-hydroxykauran-12-one、12-oxo-9,11-dehydrokaurene 和 12α-hydroxy-9,11-dehydrokaurene 的简洁且无保护基团的全合成得到进一步证明。