Theoretical studies on long-range substituent effects in the reduction of 7-norbornanones

Abstract

The energetics of the stereoselective reduction of norbornan-7-one derivatives have been studied by semiempirical AM1 molecular orbital calculations. It was found that the reaction is kinetically controlled; correct prediction of the selectivity is possible only on the basis of the relative energies of the transition states of the reaction. Theoretically calculated and experimental anti–syn product ratios are in semiquantitative agreement, in contrast to results obtained from molecular electrostatic potentials. Geometry relaxation of the transition state is essential in obtaining reliable isomer ratios.