Diels-Alder reactions involving 1,2-isopropylidenedioxy-3-trifluoromethylcyclohexa-3,5-diene

Abstract

The title compound was treated with several dienophiles to give cycloadducts resulting from addition to the less hindered face of the molecule. An exceptional case was provided by N-ethylmaleimide which added in endo-fashion to both faces of the diene. 1,2-Isopropylidenedioxy-3-trifluoromethylcyclohexa-3,5-diene acted as a dienophile on addition to cyclopentadiene and underwent dimerization to give a stable [4 + 2] adduct.