ISSN:
0749-1581
Keywords:
Cyclododeca-1,5,9-trienes
;
Z—E isomers
;
1H and 13C NMR chemical shifts
;
Vicinal 1H—1H coupling constant, 1H CW off-resonance 13C NMR spectra
;
13C/1H and 1H/1H hetero- or homocorrelated 2D NMR experiments
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The four Z—E isomers of cyclododeca-1,5,9-triene were examined by 13C NMR spectroscopy. The vicinal 1H—1H coupling constants of the olefinic protons were used to determine the stereochemistry at the double bonds. For the symmetrically substituted —CH=CH— fragments (chemically equivalent H atoms) this parameter was obtained from the 13C NMR multiplets which are observed in 1H continuous-wave off-resonance 13C NMR experiments. The precise assignment of the 1H and 13C chemical shifts, in particular for the Z,Z,E and Z,E,E isomers, was possible on the basis of off-resonance measurements in combination with 13C/1H heteronuclear correlated and 1H/1H-COSY-45 2D experiments.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260311205
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