Deconvolution of Complex NMR Spectra in Small Molecules by Multi Frequency Homonuclear Decoupling (MDEC)

A new technique to deconvolute complex H-1 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 C-16 fatty acid, demonstrate the utility of the technique. Increasing the experimental utility, the single pulse MDEC experiment can be incorporated in other 1 D experiments, such as a 1D-TOCSY to solve specific problems.