6 rangement is suggested to proceed via thermal fragmentation of the cyclopropane bond, with the transition state resembling the singlet perpendicular biradical6." Substituents on the aromatic ring can, in principle, stabilize or destabilize the transition state leading to 6 and we have used rates of this reaction as a quantitative measure of free radical stabilizing effects. This is a kinetic method for assessing the influence of Substituents on benzylic free radical ...
