Synthesis of 3-aryl- or 3-alkenyl-4,6-dimethyl-2-pyrones by silver ion promoted rearrangement of 4-aryl- or4-alkenyl-3-bromo-4,6-dimethyl-3,4-dihydro-2-pyrones

Abstract

Debromination of 4-aryl- or 4-alkenyl-3-bromo-4,6-dimethyl-3,4-dihydro-2-pyrone ( 1 ) with AgSbF 6 in dichloromethane or 1,2-dichloroethaneinduced rearrangement of the aryl or alkenyl group to the 3-position to afford the corresponding 3-substituted 2-pyrone ( 6 ) in high yield.