Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, United States.
Org Lett. 2013 Feb 15;15(4):882-5. doi: 10.1021/ol400012s. Epub 2013 Jan 24.
The acetylcholinesterase inhibitor (-)-huperzine A was synthesized from (S)-4-hydroxycyclohex-2-enone in 17 steps by a route that involved two cyclobutane fragmentations. The first of these employed a retro-aldol cleavage to generate the α-pyridone ring of huperzine A, and the second invoked a novel intramolecular aza-Prins reaction in tandem with stereocontrolled scission of a cyclobutylcarbinyl cation to create the aminobicyclo[3.3.1]nonene framework of the natural alkaloid.
乙酰胆碱酯酶抑制剂 (-)-石杉碱 A 可以由 (S)-4-羟基环己-2-烯酮经过 17 步反应合成，其中涉及两个环丁烷片段的断裂。第一个反应通过逆醛醇裂解生成石杉碱 A 的α-吡啶酮环，第二个反应通过新型的分子内氮杂-Prins 反应与立体控制的环丁基碳正离子的断裂串联，构建了天然生物碱的氨基双环[3.3.1]壬烯骨架。
