Organic Letters 2012-09-07

An efficient total synthesis of (-)-huperzine A.

Rui Ding, Bing-Feng Sun, Guo-Qiang Lin

Index: Org. Lett. 14(17) , 4446-9, (2012)

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Abstract

The total synthesis of Lycopodium alkaloid (-)-huperzine A has been accomplished in 10 steps with 17% overall yield from commercially abundant (R)-pulegone. The synthetic route features an efficient synthesis of 4 via a Buchwald-Hartwig coupling reaction, a dianion-mediated highly stereoselective alkylation of 4, and a rare example of an intramolecular Heck reaction of an enamine-type substrate. The stereoselective β-elimination and the accompanying Wagner-Meerwein rearrangement are of particular interest.