A 5–8–5-membered tricyclic diterpene, cycloaraneosene, has been totally synthesized via a stereoselective condensation of two units of optically active iridoids, a Cope rearrangement, a chemical reduction of the tetrasubstituted double bond, and the formation of an eight-membered ring. The proposed structure of natural hydroxycycloaraneosene should be revised to 8β-hydroxycycloaraneosene, judging from the NMR spectral data.
通过立体选择性缩合两个单元的光学活性虹彩、科普重排、四取代双键的
化学还原以及八元环的形成,完全合成了一种 5-8-5 元
三环二萜--环胂烯。从核磁共振光谱数据来看,拟议的天然羟基
环戊烯的结构应修改为 8β-羟基
环戊烯。