The first total synthesis of liangshanone, a hexacyclic ent‐kaurane diterpenoid alkaloid, has been completed. Its intricate cagelike framework was assembled through several key transformations, including an oxidative dearomatization/Diels–Alder (OD/DA) cycloaddition sequence, a tandem alkene cleavage/Mannich cyclization, a Robinson‐type annulation, and an intramolecular aldol reaction. Notably, an
unprecedented heptacyclic core possessing a rigid cyclopropane unit. Here, we report the first total synthesis of vilmoraconitine relying on strategic use of efficient ring-forming reactions. Key steps include an oxidative dearomatization-induced Diels–Alder cycloaddition, a hydrodealkenylative fragmentation/Mannich sequence, and an intramolecular Diels–Alder cycloaddition.
Vilmoraconitine 属于 C 19 -二萜生物碱中最复杂的骨架类型之一,其结构特征是前所未有的七环核心,具有刚性环丙烷单元。在这里,我们报告了依赖于有效成环反应的策略性使用的维莫乌头碱的首次全合成。关键步骤包括氧化脱芳构化诱导的狄尔斯-阿尔德环加成、加氢脱烯基断裂/曼尼希序列和分子内狄尔斯-阿尔德环加成。