Differentiation of meso isomers from racemic mixtures with the combined use of chiral shift reagents and two-dimensional heteronuclear correlation NMR spectroscopy
Article first published online: 12 APR 2005
Copyright © 1995 John Wiley & Sons Ltd.
Magnetic Resonance in Chemistry
Volume 33, Issue 11, pages 905–908, November 1995
How to Cite
Henrichs, P. M., Rodger, C. A., Caulfield, T. and Guo, P. (1995), Differentiation of meso isomers from racemic mixtures with the combined use of chiral shift reagents and two-dimensional heteronuclear correlation NMR spectroscopy. Magn. Reson. Chem., 33: 905–908. doi: 10.1002/mrc.1260331112
- Issue published online: 12 APR 2005
- Article first published online: 12 APR 2005
- Manuscript Received: 21 NOV 1995
- Manuscript Accepted: 18 MAY 1995
- 1H NMR;
- chiral shift reagents;
- meso isomers
In the presence of chiral shift reagents the enantiotopic nuclei of a pair of enantiomers become diastereotopic and have the potential to give resolved NMR signals. Similarly, the enantiotopic nuclei within a meso isomer become diastereotopic in the presence of a chiral shift reagent and may give resolved NMR signals. However, the diastereotopic nuclei of a meso isomer mixed with a chiral shift reagent, unlike those of a racemic mixture, are located in the same molecule. Their intramolecular character can be established experimentally by detection of spin-spin splitting between them or to a common third nucleus. Comparison of the correlation peaks in a two-dimensional, heteronuclear, multiple-quantum correlation (HMQC) spectrum with those of a heteronuclear multiple-bond correlation (HMBC) spectrum is an effective means of detection of coupling to a third nucleus. Two-dimensional NMR spectroscopy was used to identify the meso form of di-(trans-2-aminocyclohexyl)amine.