ISSN:
0749-1581
Keywords:
Heteronuclear NOE
;
Selective heteronuclear 13C{1H} NOE
;
Indirect Negative NOE
;
13C—1H—{1H} three-spin effects
;
Coumarins
;
2(1H)-Quinolones
;
Benzo[b]furans
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The 80 MHz 1H NMR and 20 MHz 13C NMR spectra of five 4-methylcoumarins, six 4-methyl-2(1H)-quinolones and nine 3-methylbenzo[b]furans, including six new compounds, were fully assigned. Homonuclear 1H{1H} NOEs and selective heteronuclear 13C{1H} NOEs were measured after low-power pre-saturation of the methyl protons. Indirect, negative heteronuclear NOE enhancements were found in suitable three-spin systems of the 13C—1H—{1H} type, and their magnitude was found to be dependent on ring size. The first examples of indirect, heteronuclear NOE enhancements on non-protonated carbons are described.
Additional Material:
12 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260260615
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