作者:Akihiro Sakama、Rika Kameshima、Yuko Motohashi、Wataru Sumida、Yuta Unno、Keisuke Yoshida、Akihiro Ogura、Ken-ichi Takao
DOI:10.1021/acs.joc.9b03114
日期:2020.3.6
Two stereocontrolled routes to the tricyclic core of (-)-callophycoic acid A are described. Our synthetic strategy relied on stereoselective allylboration using a new allylboronate reagent to construct the all-carbon quaternary stereocenter in the core, followed by efficient radical cyclization or palladium-catalyzed reductive cyclization to form its multisubstituted cyclohexane ring. The tetrahydrooxepin
描述了到(-)-苯甲酸A的三环核心的两个立体控制的路线。我们的合成策略依赖于立体选择性烯丙基硼化,使用一种新的烯丙基硼酸酯试剂在核心中构建全碳四元立体中心,然后进行有效的自由基环化或钯催化的还原环化,以形成其多取代的环己烷环。通过分子内醚化构建四氢氧杂环戊烯环。这项研究提供了第一种方法来立体选择性地合成愈伤组织酸的特征性三环骨架。