PHOTOCHEMISTRY OF CIS-1-PHENYLCYCLOHEXENE - PROOF OF INVOLVEMENT OF TRANS ISOMER IN REACTION PROCESSES

Kinetic studies showed that the formation of a [2 + 2] dimer in the direct irradiation of cis-l-phenylcyclohexene in methanol proceeds in the singlet manifold, possibly involving an excimer. The generation of a Markownikoff-type ether results from a common intermediate in the direct and the sensitized irradiation. Low-temperature studies indicate that trans-l-phenylcyclohexene is this intermediate. Evidence for the existence of a free /ra/u-1-phenylcyclohexene is found in the structure of a [4 + 2] dimer formed in irradiations of r/s-l-phenylcyclohexene in methanol at -75°C. © 1979, American Chemical Society. All rights reserved.