Quantitative 13C N.M.R. Assay and Assignment of Mixtures from Lipase Digestion of Propane-1,2-diol Dibutyrate

13C nuclear magnetic resonance (n.m.r.) spectra were obtained at 50 and 100 MHz for mixtures of propanediol, propane-1,2-diol dibutyrate, propane-1,2-diol 1-butyrate and propane-1,2-diol 2-butyrate in CDCl3. Distortionless enhancement by polarization transfer (DEPT) and two-dimensional 13C–1H correlation spectroscopy were used to confirm shift assignments. Spectra for the 1- and 2-monoesters showed strongly different inductive effects due to the position of the butyryl chain. These experiments demonstrate the desirability of using 13C n.m.r. rather than 1H n.m.r. spectroscopy in quantitative speciation of acylated diol complex hydrolysis mixtures.