The first total syntheses of the Stemona alkaloid dehydrostenine A and the structure assigned to dehydrostenine B have been completed from a simple pyrrole substrate in 10 and 11 steps, respectively. Two independent Brønsted-acid-mediated intramolecular Michael additions were exploited to construct the tetracyclic dehydrostenine core. As a result of our synthetic studies and associated analysis of the relevant literature, we propose revisions of the structures originally assigned to dehydrostenines A and B.

中文翻译：

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Dehydrostenine A 和 B 的修订结构：(±)-Dehydrostenine A 的全合成和分配给 Dehydrostenine B 的结构

百部生物碱脱氢藤碱 A的第一次全合成和脱氢藤碱 B 的结构已分别由简单的吡咯底物分 10 步和 11 步完成。两个独立的布朗斯台德酸介导的分子内迈克尔加成被用来构建四环脱氢烯核心。作为我们对相关文献的综合研究和相关分析的结果，我们建议对最初分配给脱氢烯酸 A 和 B 的结构进行修订。