Tandem intramolecular Diels-Alder/retro-Diels-Alder cycloaddition of 2H-chromen-2-one as dienes with the expulsion of CO2

A series of chiral N-allyl-N-benzylamides that contain a 2H-chromen-2-one moiety were designed for the synthesis of benzo[f]isoindol-1-ones via an intramolecular Diels-Alder and a subsequent retro-Diels-Alder reaction with the expulsion of CO2. Both the yield (80%-89%) and absolute stereocontrol of the tandem reaction were high when an electron-withdrawing group was attached to the dienophile.