Determination of relative stereochemistry
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- | The article below is the pioneering work showing that <sup>2,3</sup>J<sub>CH</sub> and <sup>3</sup>J<sub>HH</sub> coupling constants can be used to determine relative stereochemistry of two adjacent stereocenters in acyclic hydrocarbons. The analysis is based on the assumption (supported by molecular mechanics calculations) that most acyclic hydrocarbons substituted with -OH, -OCH<sub>3</sub>, -CH<sub>3</sub> and other non-bulky substituents favor gauche or anti conformations within 10<sup>o</sup> accuracy. | + | The article below is the pioneering work showing that <sup>2,3</sup>J<sub>CH</sub> and <sup>3</sup>J<sub>HH</sub> coupling constants can be used to determine relative stereochemistry of two adjacent stereocenters in acyclic hydrocarbons. The analysis is based on the assumption (supported by molecular mechanics calculations) that most acyclic hydrocarbons substituted with -OH, -OCH<sub>3</sub>, -CH<sub>3</sub> and other non-bulky substituents favor gauche or anti conformations within 10<sup>o</sup> accuracy. Also authors state that this J-based method to determine relative stereochemistry works for the cases where one rotamer is at least 85% populated. |
<bibtex> | <bibtex> |
Revision as of 02:21, 31 January 2008
This review article discusses use of 2,3JCH, 3JHH scalar couplings and 13C chemical shifts for assignment of relative stereochemistry of centers (marked in bold) in -CHX-CHY- and -CHX-CH2-CHY- hydrocarbon fragments, where X and Y are polar substituents.
2JCH couplings are useful in fragments CYH-CHX where substituent X is polar (and the coupling between atoms marked in bold is observed).
Bifulco, G., Dambruoso, P., Gomez-Paloma, L., Riccio, R.. Determination of Relative Configuration in Organic Compounds by NMR Spectroscopy and Computational Methods
Riccio, R., Bifulco, G., Cimino, P., Bassarello, C., Gomez-Paloma, L.. {Stereochemical analysis of natural products. Approaches relying on the combination of NMR spectroscopy and computational methods}
- Pure and Applied Chemistry 75(2-3):295--308, 2003
- BibTeX
Marquez, B.L., Gerwick, W.H., Williamson, R.T.. {Survey of NMR experiments for the determination of n J (C, H) heteronuclear coupling constants in small molecules}
- Magn. Reson. Chem 39:499--530, 2001
- BibTeX
The article below is the pioneering work showing that 2,3JCH and 3JHH coupling constants can be used to determine relative stereochemistry of two adjacent stereocenters in acyclic hydrocarbons. The analysis is based on the assumption (supported by molecular mechanics calculations) that most acyclic hydrocarbons substituted with -OH, -OCH3, -CH3 and other non-bulky substituents favor gauche or anti conformations within 10o accuracy. Also authors state that this J-based method to determine relative stereochemistry works for the cases where one rotamer is at least 85% populated.
Matsumori, N., Kaneno, D., Murata, M., Nakamura, H., Tachibana, K.. Stereochemical determination of acyclic structures based on carbon-proton spin-coupling constants. A method of configuration analysis for natural products
Ciminiello, P., Dell'Aversano, C., Fattorusso, E., Forino, M., Magno, S., Di Rosa, M., Ianaro, A., Poletti, R.. {Structure and Stereochemistry of a New Cytotoxic Polychlorinated Sulfolipid from Adriatic Shellfish}
Murata, M., Matsuoka, S., Matsumori, N., Paul, GK, Tachibana, K.. {Absolute configuration of amphidinol 3, the first complete structure determination from amphidinol homologues: application of a new configuration analysis based on carbon-hydrogen spin-coupling constants}
- J Am Chem Soc 121:870--871, 1999
- BibTeX