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

To study the intramolecular Diels-Alder cycloadditon of 2H-chromen-2-one as a diene, 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 cycloaddition 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. The double bond in the styrene substructure remained in the products could be further derivatized by dihydroxylation. (C) 2016 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.