The importance for cage compound formation of the oxidation potential of the enedionic system in benzoquinone–cyclopentadiene adducts

Abstract

Some substituted benzoquinone–cyclopentadiene Diels–Alder adducts do not undergo photocyclization to give cage compounds. For the adducts a parallel increase of relative quantum yield and half-peak oxidation potential, measured by cyclic voltammetry, is observed. A large difference between the energy levels of the interacting orbitals is assumed to be responsible for this lack of reactivity.