The application of two-dimensional nuclear magnetic resonance spectroscopy in computer-assisted structure elucidation

One of the most powerful tools for the determination of an unknown organic structure is two dimensional NMR spectroscopy. In some cases, this information quickly leads to a unique structure, but in many cases there remains a larger number of structural possibilities. A linked system of computer programs has been developed which uses several types of 2-D NMR data and generates all possible topological structures consistent with these data and user-input constraints. When symmetry is present, algorithms based on group theory limit the structures to those consistent with all the different symmetries that are possible. Applications of these programs to problems described in the literature, in which 2-D NMR was used to determine the structures of natural products, are described.