Divergent Total Syntheses of Enmein-Type Natural Products: (-)-Enmein, (-)-Isodocarpin, and (-)-Sculponin R

摘要

Divergent total syntheses of the enmein-type natural products (-)-enmein, (-)-isodocarpin, and (-)-sculponinR have been achieved in a concise fashion. Key features of the strategy include 1)an efficient early-stage cage formation to control succeeding diastereoselectivity, 2) a one-pot acylation/akylation/lactonization to construct the C-ring and C8 quarternary center, 3) a reductive alkenylation approach to construct the enmain D/E rings and 4) a flexible route to allow divergent syntheses of three natural products.