1 is isomerised into the pentacyclic indenoid hydrocarbon 13 (benzene, t12 (150°C) ca. 5 min), the formation of which is explained by an initial conrotatory (“symmetry-forbidden”) 18-electron electrocyclisation followed by two fast hydrogen migrations ([1.9], [1.5]) and 14π-electrocyclisation.
在热活化后,
乙烯基类十五碳烯1异构化为五环
茚满碳氢化合物13(苯,t 12(150°C),约5分钟),其形成可以通过最初的旋转(“禁止对称”)18-来解释。电子电环化之后是两个快速氢迁移([1.9],[1.5])和14π-电环化。