A novel, acid catalyzed rearrangement of the 11-trimethylsilyl-tetracyclo[8.1.0.03,7.04,11]undeca-5,8-diene ring system was observed. The trimethylsilyl substitution on the cyclopropane moiety was found to be crucial for rapid, high yielding formation of the unusual homotriquinacene ring system. The transformation is presumed to proceed via a series of carbenium ion intermediates that can be trapped with suitable nucleophiles.