Towards a Total Synthesis of Phenalinolactone Core Diterpenoid 6: Synthesis of a Racemic Decahydrobenzocyclobutaisobenzofuran with a <i>trans-anti-cis</i>
Junction of the Isocyclic Rings
作者:Thomas Hampel、Reinhard Brückner
DOI:10.1002/ejoc.201700198
日期:2017.5.26
Synthetic efforts towards the "phenalinolactone core diterpenoid 6" (5) are described. It contains a cyclohexanol (A ring), a cyclohexane (B ring), and a cyclohexene (C ring), which are angularly annulated trans and cis, respectively. What makes them unique is the trans- (or "anti"-)relationship between the A and the C ring. The trans-configured A/B ring junction was established in a novel cyclohexanone-annulation
描述了对“酚醛酸内酯核心二萜 6”(5) 的合成努力。它包含环己醇(A 环)、环己烷(B 环)和环己烯(C 环),它们分别呈反式和顺式成环。使它们独特的是 A 和 C 环之间的反(或“反”)关系。在新型环己酮环化中建立了反式配置的 A/B 环结。当尝试与不同电子需求的二烯进行分子内 Diels-Alder 反应时,C 环的反选择性顺式环化失败 (21, 31)。相比之下,基于分子内 [2+2]-光环加成的 C 环前体的反选择性顺式环化成功。它以70%的产率提供了四环38。它包含一个密集功能化的 4 元环。它应该适合开环和/或重排。因此,化合物38应该可用于在未来的工作中进行目标结构5。