Heck-Matsuda Arylation as a Strategy to Access Kavalactones Isolated from Polygala sabulosa, Piper methysticum, and Analogues

Herein, we describe the total syntheses of three bioactive pyrones isolated from Polygala sabulosa (i.e., 1, 4, and 7) and eight isolated from Piper methysticum (i.e., 810, 13, 15, and 1820) using the HeckMatsuda arylation as the key strategy. The evaluation of this methodology by employing different arenediazonium tetrafluoroborates revealed that the Heck arylation was more efficient when the olefin undergoing arylation possessed the vinyl-2-pyrone structural unit instead of the vinyl dihydro-2-pyrone moiety. The HeckMatsuda arylation of many of the examined olefins proceeded in a practical manner with total regio- and stereocontrol.