Determination of absolute configurations and conformations of organic compounds by theoretical calculations of CD spectra
The usefulness and limitations of the CNDO/S method for calculations of rotational strengths of inherently chiral chromophores are illustrated with examples from bridged biphenyls. The more empirical Schellman matrix method is employed to calculate CD spectra of compounds containing two chirally disposed chromophores. Analysis of the CD spectra of a compound containing two interacting thioamide groups gives detailed conformational information. Analysis of the CD spectra of two closely analogous 1,2,3, 4-tetrahydro-2-aryl-N-formyl-pyridines with spiro structure shows how a small structural change can lead to the appearance of a nearly mirror image CD spectrum with retained configuration at the spiro atom. Copyright 2000 Wiley-Liss, Inc.
Sandstrom
J
Division of Organic Chemistry 1, Center for Chemistry and Chemical Engineering, University of Lund, Lund, Sweden.