Photochemically Induced Ionic Reactions of Cycloalkenes

Science  09 Oct 1970:
Vol. 170, Issue 3954, pp. 137-141
DOI: 10.1126/science.170.3954.137


Sensitized ultraviolet irradiation of cyclohexenes and cycloheptenes in protic solvents causes reactions which seemingly proceed by way of carbocation intermediates. These intermediates, in turn, may arise from a photochemically produced trans cycloalkene which is so highly strained that protonation by even weak acids such as methanol may proceed readily. This picture is supported by product analysis, deuterium labeling experiments, and stereochemical studies.