SPONGIAN PENTACYCLIC DITERPENES - STEREOSELECTIVE SYNTHESIS OF (-)-DENDRILLOL-1
SPONGIAN PENTACYCLIC DITERPENES - STEREOSELECTIVE SYNTHESIS OF (-)-DENDRILLOL-1
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DOI：
10.1021/jo00051a035
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发表时间：
1992-12-04
影响因子：
3.6
通讯作者：
ZARAGOZA, RJ
中科院分区：
文献类型：
--
作者：
ABAD, A;ARNO, M;ZARAGOZA, RJ
本文报道了海绵二萜（-）-dendrillol-1（3）的全合成方法，该方法可用于其它五环海绵二萜的合成。该合成是基于酸-二醛4的分子内缩醛化，该酸-二醛4是由（+）-罗汉果-8（14）-烯-13-酮（5）通过一系列转化制备的，所述转化包括（a）通过与乙炔的光化学反应在5上引入潜在的二醛单元，（B）在光加合物6的C-13处还原羧化以获得酸18，和（c）通过臭氧分解在18的C-8和C-14处制备二醛部分。几个程序，已被检查为6的C-13还原羧化的描述。还报道了一个简单的三步程序，以实现将罗汉果-8-烯-13-酮系统转化为C-17-官能化的beyerane化合物。
A formal total synthesis of the spongian diterpene (-)-dendrillol-1 (3), through a consice approach that could be used for the synthesis of other pentacyclic spongian diterpenes, is reported. The synthesis is based on the intramolecular acetalization of an acid-dialdehyde 4, which is prepared from (+)-podocarp-8(14)-en-13-one (5) via a sequence of transformations involving (a) introduction of a latent dialdehyde unit on 5 by photochemical reaction with acetylene, (b) reductive carboxylation at C-13 of photoadduct 6 to obtain acid 18, and (c) elaboration of the dialdehyde moiety at C-8 and C-14 of 18 by ozonolysis. Several procedures that have been examined for the reductive carboxylation at C-13 of 6 are described. A simple three-step procedure to effect the conversion of a podocarp-8-en-13-one system into a C-17-functionalized beyerane compound is also reported.