State Key Laboratory of Bioorganic & Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Lu, Shanghai 200032, China.
J Am Chem Soc. 2017 Mar 1;139(8):2932-2935. doi: 10.1021/jacs.7b00140. Epub 2017 Feb 14.
The Hoppe's homoaldol reaction of a cyclo-hexenyl carbamate with an aldehyde followed by an unprecedented BF·OEt mediated intramolecular Mukaiyama-Michael-type reaction affords the tetracyclic core structure of ent-kaurane diterpenoids. The usage of this convergent approach for assembling these natural products is demonstrated by the first asymmetric total syntheses of two highly oxidized ent-kaurane diterpenoids: Lungshengenin D and 1α,6α-diacetoxy-ent-kaura-9(11),16-dien-12,15-dione.
环己烯基氨基甲酸酯与醛的霍普反应，接着是前所未有的 BF·OEt 介导的分子内 Mukaiyama-Michael 型反应，提供了-ent-贝壳杉二萜的四环核心结构。这种收敛方法用于这些天然产物的组装，通过首次不对称全合成两种高度氧化的-ent-贝壳杉二萜：Lungshengenin D 和 1α,6α-二乙酰氧基-ent-贝壳杉-9(11),16-二烯-12,15-二酮，得到了证明。
