10.1021/ja00290a042
The research investigates the acetolysis of a series of bicyclo[n.1.0]alkanes and [n.m.1]propellanes to understand the factors influencing the rates and products of these reactions. The study aims to determine the role of ring strain, ionization potentials, and bond polarization in the acetolysis process. Key chemicals used include various cyclopropane derivatives such as bicyclo[3.1.0]hexane, [3.2.1]propellane, and [4.2.1]propellane, with acetic acid serving as the solvent and p-toluenesulfonic acid as the catalyst. The researchers found that, contrary to expectations, strain energy relief has little correlation with reaction rates, while ionization potentials show a rough correlation. The degree of C-C bond polarization in the presence of a proton is a significant factor controlling the acetolysis rates. The study concludes that polarization of the central bond, influenced by the energy gap between occupied and unoccupied orbitals, is crucial for the reactivity of cyclopropanes. This finding highlights the importance of electronic factors over structural strain in determining reaction outcomes.