Formal Synthesis of Pseudolaric Acid B

Abstract

A formal synthesis of pseudolaric acid B, a diterpene isolated from the root bark of Pseudolarix kaempferi Gordon (Pinaceae), to Trost's synthetic intermediate was achieved in 17 steps from a known ketone. Key features of this synthesis include a Claisen rearrangement and iodoetherification to construct quaternary stereocenters and ring-closing metathesis to form the seven-membered ring.