Total Syntheses of Phleghenrines A and C: A [4 + 2] Cycloaddition and Ring-Expansion Approach

作者：Hongliang Shi, Huachen Hou, Jinbo Duan, Jinwei Huang, Xiaoguang Duan, Xingang Xie, Huilin Li, Xuegong She · 发表于：Organic Letters · 年份：2023 · DOI：10.1021/acs.orglett.3c00755 · 被引用次数：10 · 研究领域：Cholinesterase and Neurodegenerative Diseases、Chemical synthesis and alkaloids、Allelopathy and phytotoxic interactions

The first total syntheses of Lycopodium alkaloids phleghenrines A and C have been accomplished in 19 and 18 steps, respectively, relying on three (hetero)-Diels–Alder ([4 + 2]) cycloaddition reactions to forge the cyclic molecular backbone and two ring-expansion reactions to manipulate the ring size. A chiral precursor is synthesized through an auxiliary controlled Diels–Alder reaction, rendering the asymmetric synthesis accessible. The established strategy provides a general approach to the relevant novel Lycopodium alkaloids.