Diels-Alder Reactions of Styrylcyclohexenones: an Efficient Procedure for the Synthesis of Substituted Dehydrodecaline Derivatives

The Diels-Alder reaction of styrylcyclohex-2-enone derivatives 1 with N-phenylmaleimide was shown to be an efficient pathway for the synthesis of substituted dehydrodecaline derivatives. At elevated temperatures, mixtures of endo/exo adducts were formed, while in the presence of TiCl4 exclusive formation of the endo stereoisomer was observed. Spectroscopic analysis and X-ray crystallography confirmed the formation of the endo adducts.