Abstract

A facile method for the preparation of chiral pyrone derivatives through hetero-Diels-Alder reaction is described. Sodium alcoholates were used as efficient additives in the enantioselective reactions catalyzed by MCl4 (M = Ti4+, Sn4+) / (R)-BINOL systems. The optically resulted active 2, 6-disubsituted dihydropyrones could be obtained with up to 94% ees and 88% yields.

Keywords: HDA reaction, dihydropyrones, enantioselective synthesis, BINOL, Na alcoholate