Methodological strategy in locating transition states. Cyclization of the carbonyl ylide CH2O+–CH2– and its cycloaddition to ethylene

Abstract

Taking into account the four conditions required by Mclver and Komornicki to characterize a transition state, the most convenient technique for locating the transition states of the cyclization of the carbonyl ylide CH₂O⁺–CH₂^– and of its 1,3-dipolar cycloaddition to ethylene is discussed, taken as examples for electrocyclic reactions and for cycloadditions, respectively. The strategy adopted seems to be adequate for studying any reaction.