Molecular structure of methyl phenylpyruvates studied by 1H NMR and IR spectroscopies and quantum mechanical calculations

Abstract Molecular structure of methyl phenylpyruvate (MPP) and its p -substituted derivatives has been investigated by 1 H NMR and IR spectroscopies. The spectral data point out that MPPs take the enol form both in solution and in the solid state. The ab initio calculations were carried out in order to get information on the configurational and conformational 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.