Dipartimento di Chimica, Università degli Studi di Roma La Sapienza, P.le Aldo Moro, 5, I-00185 Roma, Italy.
J Org Chem. 2011 Aug 19;76(16):6871-6. doi: 10.1021/jo200945s. Epub 2011 Jul 19.
The problem of constructing diastereoselectively the C/D ring system of stemarane diterpenes from a bicyclo[2.2.2]octane intermediate was solved resulting in very simple synthesis of (+)-13-stemarene 1. The obtaining of the latter represents also a formal synthesis of (+)-18-deoxystemarin 2. In the key step, the epimeric mixture 10, dissolved in toluene, was converted by the action of TsOH into (+)-stemar-13-en-15-one 28.
从双环[2.2.2]辛烷中间体构建甾体二萜的 C/D 环系统的非对映选择性问题得到了解决，从而非常简单地合成了 (+)-13-石蒜烯 1。后者的获得也代表了 (+)-18-去氧石蒜素 2 的形式合成。在关键步骤中，将外消旋混合物 10 溶解在甲苯中，用 TsOH 作用转化为 (+)-石蒜-13-烯-15-酮 28。
