Determination of relative stereochemistry

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<sup>2</sup>J<sub>CH</sub> couplings are useful in fragments CY'''H'''-'''C'''HX where substituent X is polar (and the coupling between atoms marked in bold is observed).
<sup>2</sup>J<sub>CH</sub> couplings are useful in fragments CY'''H'''-'''C'''HX where substituent X is polar (and the coupling between atoms marked in bold is observed).
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@article{bifulco2007drc,
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#bifulco07 bibtex=@article{bifulco2007drc,
title={Determination of Relative Configuration in Organic Compounds by NMR Spectroscopy and Computational Methods},
title={Determination of Relative Configuration in Organic Compounds by NMR Spectroscopy and Computational Methods},
author={Bifulco, G. and Dambruoso, P. and Gomez-Paloma, L. and Riccio, R.},
author={Bifulco, G. and Dambruoso, P. and Gomez-Paloma, L. and Riccio, R.},
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url={http://pubs3.acs.org/acs/journals/doilookup?in_doi=10.1021/cr030733c}
url={http://pubs3.acs.org/acs/journals/doilookup?in_doi=10.1021/cr030733c}
}
}
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</bibtex>
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#riccio03 bibtex=@article{riccio2003san,
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<bibtex>
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@article{riccio2003san,
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title={{Stereochemical analysis of natural products. Approaches relying on the combination of NMR spectroscopy and computational methods}},
title={{Stereochemical analysis of natural products. Approaches relying on the combination of NMR spectroscopy and computational methods}},
author={Riccio, R. and Bifulco, G. and Cimino, P. and Bassarello, C. and Gomez-Paloma, L.},
author={Riccio, R. and Bifulco, G. and Cimino, P. and Bassarello, C. and Gomez-Paloma, L.},
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year={2003}
year={2003}
}
}
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#marquez bibtex=@article{marquez2001sne,
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<bibtex>
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@article{marquez2001sne,
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title={{Survey of NMR experiments for the determination of n J (C, H) heteronuclear coupling constants in small molecules}},
title={{Survey of NMR experiments for the determination of n J (C, H) heteronuclear coupling constants in small molecules}},
author={Marquez, B.L. and Gerwick, W.H. and Williamson, R.T.},
author={Marquez, B.L. and Gerwick, W.H. and Williamson, R.T.},
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year={2001}
year={2001}
}
}
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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. Also authors state that this J-based method to determine relative stereochemistry works for the cases where one rotamer is at least 85% populated.
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.

Revision as of 20:47, 23 April 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).

  1. Bifulco, G and Dambruoso, P and Gomez-Paloma, L and Riccio, R. Determination of Relative Configuration in Organic Compounds by NMR Spectroscopy and Computational Methods. Chem Rev 107(9):3744--79, 2007. BibTeX [bifulco07]
  2. Riccio, R and Bifulco, G and Cimino, P and Bassarello, C and 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 [riccio03]

  3. Marquez, BL and Gerwick, WH and Williamson, RT. 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 [marquez]


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

J. Org. Chem 64(3):866--876, 1999
WWW | BibTeX

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}

Journal of the American Chemical Society 124(44):13114--13120, 2002
WWW | BibTeX

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


The following article shows how the relative stereochemistry of 1,3-diols may be determined as syn- or anti- by analyzing the carbon shifts after functionalizing the 1,3-diols to acetonides. If the 1,3-diols have a syn- orientation to one another, the acetonide will have a chair conformation and the methyl carbons of the acetonide will have different shifts due to one being axial, the other being equitorial. If the diols are anti-, then the acetonide will exist as a twist boat conformation and the methyl carbons will have similar carbon shifts.

Rychnovsky, S.D., Rogers, B., Yang, G.. {Analysis of two carbon-13 NMR correlations for determining the stereochemistry of 1, 3-diol acetonides}

The Journal of Organic Chemistry 58(13):3511--3515, 1993
BibTeX

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