PMO-treatment of the structure-reactivity relationships in free radical addition reactions of cycloalkenes

The effect of ring strain in molecules of C5-C8 cycloalkenes and that of electronegativity of the attacking radicals upon reactivity of cycloalkenes in 1,2 addition reactions was studied by using a simple perturbation approach. The trends of the experimentally determined reactivities of cycloalkenes towards CH3, CCl3, CF2CF2CF3, CH3CO, NCCHCO2H5, C2H5, C2H5S and Br radicals were found to be in an acceptable agreement with the trends of the calculated Fukui's delocalisabilities Dr. The reactivity of cycloalkenes appears to be influenced by I-strain in the cycloalkene molecules as well as by electronegativity of the attacking radicals.