Visible-light-induced alkoxycarbonylation/cyclization of 1,7-enynes: synthesis of dihydropyranones containing all-carbon quaternary centers

Abstract

A direct photoredox catalyzed radical-triggered tandem cyclization of 1,7-enynes with alkyloxalyl chlorides is developed. With this approach, a variety of dihydropyranones containing all-carbon quaternary centers are prepared through alkoxycarbonylation/6-exo-dig cyclization/6-endo-trig cyclization with 1,7-enynes under mild conditions. More importantly, this approach provides a new route to polysubstituted dihydropyranones.