ISSN:
1573-8353
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract A simple and convenient method is proposed for determining the configuration of E,Z-isomers of 2-, 3-, and 4-benzoylpyridines. The difference in chemical shifts (δδ, ppm) in the system CCl4-DMSO-D6 and CCl4-DMSO-CF3COOD for the α-H atoms or the α, Β-C atoms of the pyridine ring can be used to determine the configuration. The shift (δδ) of the α-H signals to weak field is greater for the Z-isomers than for the E-isomers due to protonation of the pyridine nitrogen atom. The reverse dependence is seen in the 13C NMR for the E,Z-isomers. The signals of the α-C atoms shift to stronger field after protonation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00480866
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