A Convenient Synthesis of 3-Substituted-5, 5-dimethyl-tetrahydro-2-benzopyran-8-ones Through Hetero-Diels-Alder Reaction

Abstract
2-Formyl-4,4-dimethylcyclohexa-2,5-dien-1-one undergoes hetero-Diels-Alder reactions with electron-rich olefins to yield 3-substituted-5,5-dimethyl-3,4,4a,5-tetrahydro-8H-2-benzopyrane-8-ones. The endo addition is favoured