Phorbol (1) has a tetracyclic ABCD-ring and is readily isolable from a natural source. We previously synthesized 1 and 16 structurally related natural products using common ABC-ring intermediate 2. Here we report a new synthetic route to 2 using 1 as a starting material. Key features of the synthesis are chemoselective removal of the D-ring via cyclopropane opening, peroxidation, and retro-aldol reactions. The high utility of the peroxidation was further demonstrated in the first synthesis of crotonianoid B (9).

中文翻译：

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佛波醇通过过氧化反应转化为 Des-D-Ring 三环和巴豆素 B


佛波醇 (1) 具有四环 ABCD 环，很容易从天然来源中分离出来。我们之前使用常见的ABC环中间体2合成了1和16个结构相关的天然产物。在这里，我们报告了使用1作为起始原料合成2的新路线。该合成的关键特征是通过环丙烷开环、过氧化和逆羟醛反应化学选择性去除 D 环。巴豆酸 B 的首次合成进一步证明了过氧化反应的高实用性 (9)。