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

Abstract

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.