A two step, non-stereospecific cation radical Diels-Alder reaction

Article abstract of DOI:10.1016/S0040-4039(99)01842-0

The cation radical Diels-Alder cycloadditions of cis- and trans-1-propenyl aryl ethers to 1,3-cyclopentadiene, catalyzed by tris(4-bromophenyl)aminium hexachloroantimonate in dichloromethane solution, are found to be non-stereospecific, in contrast to the stereospecificity observed in other cation radical Diels-Alder reactions previously studied. These and supporting experiments indicate that, in this particular system, the reaction occurs by a two step mechanism.