Photochemical Rearrangement of Benzyl Phenyl Ether

Abstract

Photochemical rearrangement of benzyl phenyl ether has been studied. The photolysis of benzyl ether in organic media gave o- and p-benzylphenols. phenol and bibenzyl. In the case of photolysis in isopropanol, the yields of o- and p-benzylphenols . and phenol were 28.5, 16.9, and 15.8%, respectively. The hydrogen-donating alcohols, such as menthanol, ethanol, isopropanol, and grycerol-isopropanol, were effective as solvents for the photorearrangement was not quenched by triplet quenchers. Yields of the rearrangement products decreased by the radical inhibitors, such as 2, 2-diphenyl-1-picrylhydrazyl and nitoro-sobenzene. On the other hand, the yields increased with the viscosity of solvents. These results suggest that benzyl phenyl ether in π, πlowest excited singlet state gives a radical pair, which couples in a solvent cage to form o- and p-benzylphenols.