The solvent effect of phenols on the reactivity and periselectivity for the pericyclic reactions of cyclopentadienones with olefins involving conjugated medium-ring polyenes has been investigated. The use of phenols as a solvent accelerates the reaction rates of cycloadditions of cyclopentadienones with nonactivated olefins. In the reaction of cycloheptatriene in p-chlorophenol, the exo [4+ 6] π cycloadduct was produced ...
