The photochemistry of o-allylphenol (la) and its derivatives has been extensively investigated. l-1 In general, photocyclization to dihydrobenzofurans 2 and dihydrobenzopyrans 3 has been explained through intramolecular proton transfer from the excited phenol to the ground state olefin. However, an alternative mechanistic pathway might involve excited state electron transfer within the same donor-acceptor pair. g In this ...
