Conformational analysis, tautomerization, IR, Raman, and NMR studies of ethyl benzoylacetate

A complete conformational analysis of the keto and enol forms of ethyl benzoylacetate (EBA), a β-ketoester, was carried out by ab initio calculations, at the density functional theory (DFT) level. The relative stabilities of cis-enol and keto forms were calculated in the gas phase and in solution. The intramolecular hydrogen bond characters of the most stable enol forms of EBA are discussed and compared with those of benzoylacetone (BA). ic vibrational frequencies and 1H and 13C NMR chemical shifts of the most stable enol and keto forms were also calculated at the B3LYP/6-311++G** level and compared with the experimental data.