Total Synthesis of (-)-Anominine with an Organocatalytic Key Step

Significance

A concise 22-step total synthetic approach to (-)-anominine is reported. The first step of the synthesis is an organocatalytic ­Robinson annulation of a 1,3-diketone with ­methylvinyl ketone using prolinamide 1 as catalyst. The catalyst loading is remarkably low; only 1 mol% is necessary to furnish the first key intermediate in high yield with excellent enantioselectivity. After setting the first stereocenter, further transformations, among them a remarkable ;[2,3]-sigmatropic rearrangement of an allylic selenide, exploit the structurally congested nature of this bicyclic core for diastereoselectivity.