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1997
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In the Laboratory
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Carbon-Carbon and Carbon-Nitrogen Spin-Spin Coupling in NMR Spectroscopy: Simple Examples Based on Isotope-Labeled Glycines
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Leif Grehn, Ulf Ragnarsson, and Christopher J. Welch
Organic Pharmaceutical Chemistry, Uppsala Biomedical Centre, Department of Pharmaceutical Chemistry, Uppsala Biomedical Centre, Box 574, Uppsala S-751 23
SWEDEN
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December 1997
Vol. 74 No. 12
p. 1477
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| Abstract |
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The phenomena of carbon-carbon and carbon-nitrogen spin-spin coupling, not visible in 13C and 15N NMR spectra recorded at natural abundance, are demonstrated using routine conditions primarily in a series of 13C/15N-labeled t-butoxycarbonyl- glycine isotopomers. Doublet and doublet of doublet signals, originating from one and two bond homo- and/or heteronuclear spin-spin coupling, are thereby obtained. Furthermore, from all these NMR spectra the presence of each isotopomer in two con formations is clearly demonstrated. Such compounds are in principle easy to make, but preparative work especially involving the 13C nucleus is costly, for which reason two other more affordable alternatives are also presented, based only on 15N labeling, in which cases 13C nuclei directly attached to 15N give rise to doublet signals. These two preparations can conveniently be performed on a small scale. The first one involves the synthesis of a 15N-labeled imidodicarbonate, whereas the second demonstrates its efficient alkylation under simple phase-transfer catalysis conditions.
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| More Information |
 Citation |
Grehn, Leif; Ragnarsson, Ulf; Welch, Christopher J. J. Chem. Educ. 1997 74 1477.
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Keywords |
NMR Spectrometry, Instrumental Methods, Isotopes, Organic Chemistry, and Laboratory Instruction
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History |
Created:
Last Updated: |
July 20, 1999
November 22, 2005
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| Home > JCE Print > Journal of Chemical Education > Issues >
1997
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December
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1477
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