Reactive cleavage of epoxides. Molecular mechanics model for regiochemical control of the ring-opening reactions

Abstract

A molecular mechanics model has been developed to predict the relative activation energies of nucleophilic (LiAIH₄) ring-opening reactions of epoxides leading to regioisomeric products. The model developed is entirely empirical, representing linear combination of calculated steric-hindrance and product-stability effects. The conformational, steric and electronic effects in the transition state, calculated by MM2, enable prediction of product distribution in 19 ring-opening reactions.