Highly regio- and stereoselective Heck reaction of allylic esters with arenediazonium salts: application to the synthesis of kavalactones.

A highly efficient palladium-catalyzed Heck reaction of allylic esters with arenediazonium salts is described. The reaction proceeds under mild conditions, with excellent to total regio- and stereochemical control and with retention of the traditional leaving group. Furthermore, the generality of the present methodology is illustrated by the short total synthesis of the natural kavalactones, yangonine, (+/-)-methysticin, and (+/-)-dihydromethysticin.