Total Synthesis of (+)-Hydroxyjatrophone a and (+)-Hydroxyjatrophone B

A full account of the first total synthesis of (+)-hydroxyjatrophone A (2) and (+)-hydroxyjatrophone B (3), two antileukemic diterpene macrocycles isolated from Jatropha gossypiifolia, is presented. Central to the synthetic strategy was an intramolecular Mukaiyama acetal-aldol reaction that generated the 11-membered ring. Of paramount interest with respect to the hydroxyjatrophones was the compatibility of the highly sensitive, tertiary allylic hydroxyl group with the required end-game transformations. Completion of this synthetic venture dramatically demonstrates the versatility of our jatrophone synthetic strategy.