Two synthesis designs for the diterpenoid crotogoudin are discussed, and efforts to achieve each are described. First, a Cope rearrangement/intramolecular Diels–Alder cascade reaction was investigated. Second, a bioinspired sequence of cationic bicyclization and A-ring oxidative fragmentation set-up for a lactonization induced by a phenolic oxidation, ultimately providing a tricyclic intermediate that required only installation of the bridging ring of the salient bicyclo[2.2.2]octane system. This last endeavor was fraught with difficulty, but did lead to the development of conditions for cyclization of related keto-alkenes via manganese(III)-based radical chemistry.

中文翻译：

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努力合成 Crotogoudin 和 Crotobarin

讨论了二萜类 crotogoudin 的两种合成设计，并描述了实现每一种的努力。首先，研究了Cope重排/分子内Diels-Alder级联反应。其次，由酚氧化诱导的内酯化的阳离子双环化和 A 环氧化断裂设置的生物启发序列，最终提供了一个三环中间体，只需要安装突出的双环 [2.2.2] 辛烷系统的桥环. 这最后的努力充满了困难，但确实导致了相关酮烯烃通过基于锰（III）的自由基化学环化的条件的发展。