Total Synthesis of Paralemnolide A

The first total synthesis of tricyclic bisnorsesquiterpene paralemnolide A, isolated from the soft coral Paralemnalia thyrsoides, was achieved. This synthesis features the lactonization of the cyclohexene derivative having a tert-butyl ester via stereoselective epoxidation followed by treatment with a Brønsted acid and construction of the novel tricyclic skeleton by an intramolecular Reformatsky-Honda reaction.