FACE SELECTIVITY IN ELECTROPHILIC ADDITIONS TO METHYLENENORSNOUTANES - RELATIVE IMPORTANCE OF THROUGH-SPACE, THROUGH-BOND AND ELECTROSTATICINTERACTIONS

4-Substituted 9-methylenenorsnoutanes undergo a variety of electrophil ic additions with a small but consistent syn preference; ab initio MES P maps indicate that electrostatic factors and through-space interacti on between the double bond and cyclopropane Walsh orbitals are unimpor tant in determining the face selectivity, while AM1 transition state e nergetics suggest that the observed preferences are determined primari ly by through-bond interactions.