An efficient and stereoselective synthesis of xerulin via Pd-catalyzed cross coupling and lactonization featuring (E)-iodobromoethylene as a novel two-carbon synthon

[GRAPHICS] Xerulin, an inhibitor of cholesterol biosynthesis, has been synthesized fro m commercially available (E)-1-bromopropene, acetylene, and propynoic acid in five steps (longest linear sequence) in 30% overall yield and >96% stere oselectivity, The preparation of (E)-iodobromoethylene and its use in the P d-catalyzed cross coupling are two of the novel aspects of the synthesis re ported herein.