STUDIES IN THE CYCLOPROPARENE SERIES - REACTIONS WITH RADICALS

The behaviour of 1H-cyclopropabenzene (1) and 1H-cyclopropa[b]naphthalene (23) towards a variety of radicals results in opening of the three-membered ring to give ortho-substituted benzyl and 2-methylnaphthalene derivatives, e.g. (13) and (28), respectively. Ring expansion into the cycloheptatriene manifold by way of addition to the bridge bond and norcaradiene formation have not been observed. Analogous reactions with the methylidenecyclopropa[b]naphthalenes (33) and (34) lead to much decomposition, and provide little evidence for the C1 cycloproparenyl radicals (35) and (36).