Acid-catalysed rearrangement of a number of polycyclic cross-conjugated methylenecyclohexadienes possessing an angular methyl group (for example (I)) has led to the corresponding substituted 1,4-dimethylbenzenes. The reaction parallels the dienone-phenol rearrangement, but, unlike the latter, the course of the rearrangement is not sensitive to the reaction conditions.