Hydration of pyruvic acid to its geminal-diol, 2,2-dihydroxypropanoic acid, in a water-restricted environment

In this work we present the spectroscopic characterization of 2,2-dihydroxypropanoic acid and its water complexes. Based on this information the water-mediated hydration between pyruvic acid and its geminal diol counterpart, 2,2-dihydroxypropanoic acid, was investigated at very low water concentration at ambient temperatures, using Fourier-transform mid-infrared (FTIR) and nuclear magnetic resonance spectroscopy (NMR). We experimentally observed large concentrations of 2,2-dihydroxypropanoic acid in this water-restricted environment of the carbon tetrachloride matrix. Our observation can be explained by the role of hydrogen-bonded water clusters in promoting the hydration of the carbonyl in pyruvic acid.

47Highlights► We obtained the first IR spectra of 2,2-dihydroxypropanoic acid. ► The first IR spectra of pyruvic and 2,2-dihydroxypropanoic acid water complexes. ► The hydration of pyruvic acid occurs at low water concentration. ► Hydrogen-bonded water clusters are important in promoting hydration of pyruvic acid. ► This water mediated reaction is important in atmospheric chemistry.