Electron deficient dienes I. Normal and inverse electron demand Diels-Alder reaction of the same carbon skeleton

Abstract

The synthesis of compound 11, which features a diene moiety bearing electron withdrawing groups at the 1 and 3 positions, and its completely regioselective inverse electron demand Diels-Alder reactions with 1,1-diethoxyethylene, ethyl vinyl ether and styrene are described. Endo addition is preferred. The direct synthetic precursor of 11, in which one of the electron withdrawing groups (a ketone) is protected, participates in normal electron demand Diels-Alder reactions with 1,4-naphthoquinone and N-phenylmaleimide, but is unreactive towards 1,1-diethoxyethylene.