MOLECULAR-STRUCTURE OF METHYL PHENYLPYRUVATES STUDIED BY H-1-NMR AND IR SPECTROSCOPIES AND QUANTUM-MECHANICAL CALCULATIONS

Molecular structure of methyl phenylpyruvate (MPP) and its p-substitut ed derivatives has been investigated by H-1 NMR and IR spectroscopies. The spectral data point out that MPPs take the enol form both in solu tion and in the solid state. The ab initio calculations were carried o ut in order to get information on the configurational and conformation al preferences in the enol form. It is suggested from the calculation that the inter- and intra-molecular hydrogen bondings between the enol OH group and the ester C = O group are important for stabilization of the conformer. (C) 1998 Elsevier Science B.V. All rights reserved.