作者:Ting-Zhong Wang、Emmanuel Pinard、Leo A. Paquette
DOI:10.1021/ja9533609
日期:1996.1.1
dimethylacetamide at 220 °C promotes sequential 1,2-elimination and Claisen rearrangement. The cyclooctenone core of the target is formed in this step. The final stages of the synthesis involve a series of fully stereoselective reactions including Simmons−Smith cyclopropanation and controlled Dibal-H reduction. The naturally occurring dextrorotatory enantiomer of acetoxycrenulide was ultimately acquired
描述了对海洋毒素 (+)-acetoxycrenulide 的对映选择性途径。合成的早期阶段将 (R)-香茅醇转化为丁烯内酯,其唯一立体中心由萜烯醇提供。三个连续的手性碳原子随后通过对映纯烯丙基膦酰胺试剂的共轭加成设置为必需的绝对构型。所得产物在几个步骤中转化为初级氧化硒,其在二甲基乙酰胺中在 220°C 下的热活化促进了连续的 1,2-消除和克莱森重排。目标的环辛酮核在这一步形成。合成的最后阶段涉及一系列完全立体选择性的反应,包括 Simmons-Smith 环丙烷化和受控的 Dibal-H 还原。