DFG research group FOR 934 (April 2008 – April 2014)
Relative and absolute configurations of dissolved molecules by NMR-spectroscopy in orienting media.
Excerpt from the closing report: The goal of the research group was the development of a general and versatile method for the computer aided NMR-spectroscopic determination of relative and absolute configurations of natural products and other organic compounds using anisotropic NMR-parameters like residual dipolar couplings, RDCs and residual chemical shift anisotropy, RCSA. Moreover, the development of achiral and chiral alignment media for this purpose was intended. Despite considerable progress in the structural characterization of biomacromolecules, the determination of relative and absolute configurations of arbitrary molecules is still a formidable challenge. In this context structurally relevant parameters like RDCs, applicable without prior parametrization and being independent from breaks in the J- or NOE-connectivity, are of special importance. This latter point is a particular problem when the assignment of the configuration of unknown stereogenic units is the problem to be solved. This is especially true if the stereogenic units are far apart from each other. To reach this goal and to meet the need for multi alignment data sets from independently orienting media it is necessary to develop new chiral and achiral media as well as new methods for the measurement, interpretation and prediction of anisotropic NMR-parameters. In detail the following research goals were defined: