Deconvolution of Complex NMR Spectra in Small Molecules by Multi Frequency Homonuclear Decoupling (MDEC)
Ana Paula D. M. Espindola†, Ronald Crouch‡, John R. DeBergh†, Joseph M. Ready† and John B. MacMillan*†
A new technique to deconvolute complex 1H NMR spectra of small molecules has been developed that utilizes shape selective pulses to simultaneously decouple multiple protons. A limitation in the assignment of the relative configuration of small molecules is the ability to accurately obtain coupling constants. Other methods such as the E.COSY and the 2D J-resolved are available to obtain complicated coupling constants; the multiple homonuclear decoupling method (MDEC) described is a rapid and simple technique. Three examples of increasing spectral complexity, menthol, cholesteryl acetate and a C16 fatty acid, demonstrate the utility of the technique. Increasing the experimental utility, the single pulse MDEC experiment can be incorporated in other 1D experiments, such as a 1D-TOCSY to solve specific problems.