Electrostatic vs. Orbital Control of Facial Selectivities in π Systems: Experimental and Theoretical Study of Electrophilic Additions to 7‐Isopropylidenenorbornanes

Abstract

Predominantly orbital effects determine the pre ferred syn attack of electrophiles on the norbornane derivative 1 bearing an electron-withdrawing endo substituent. This finding is the result of topological analyses of the electrostatic potentials from ab initio calculations and a comparison of the energies of the transition states calculated with semiempirical methods. R = CN, COOCH3.