SYNTHETIC STUDIES ON THE GINKGOLIDES - TOTAL SYNTHESIS OF (+/-)-BILOBALIDE
SYNTHETIC STUDIES ON THE GINKGOLIDES - TOTAL SYNTHESIS OF (+/-)-BILOBALIDE
复制标题
DOI：
10.1021/ja00061a014
复制
发表时间：
1993-04-21
影响因子：
15
通讯作者：
GRAY, JL
中科院分区：
文献类型：
--
作者：
CRIMMINS, MT;JUNG, DK;GRAY, JL
介绍了 C15 银杏内酯（白果内酯）的两种合成方法。 一种方法通过在 Corey 合成中交叉中间体来产生正式合成，而第二种方法则产生比第一种方法短得多的完整全合成。这两种方法都依赖于立体选择性分子内 [2 + 2] 光环加成来控制大部分立体化学。非对映选择性羟醛缩合用于建立第二种方法中仲醇和叔醇之间的相对立体化学关系。这避免了在先前的两种方法中遇到的加入叔甲醇的问题。
Two syntheses of the C15 ginkgolide, bilobalide, are presented. One approach results in a formal synthesis by intersecting an intermediate in the Corey synthesis, while a second approach results in a completed total synthesis which is considerably shorter than the first. Both approaches rely on a stereoselective intramolecular [2 + 2] photocycloaddition to control much of the stereochemistry. A diastereoselective aldol condensation serves to establish the relative stereochemical relationship between the secondary and tertiary alcohols in the second approach. This circumvents problems of incorporation of the tertiary carbinol which were encountered in both previous approaches.