Ab Initio Molecular Orbital Study of the Reactivity of Active Alkyl Groups. VII. Solvent Effects on the Formation of Enolate Isomers from 2-Butanone with Methoxide Anion in Methanol

Abstract

The mechanism of the deprotonation of 2-butanone (1) with methoxide anion (2) was studied by ab initio molecular orbital (MO) methods. Calculations of the thermodynamic stabilities of each complex and the regioselectivity of the reaction were performed using a static isodensity surface polarized continuum model (IPCM) which takes the solvent effect into consideration. The calculated energies of the complexes lead ultimately to the conclusion that the major deprotonation pathway in protic solvents is dependent upon thermodynamically stable complexes with small activation energies under equilibrium control.