ISSN:
0749-1581
Keywords:
Piperidines
;
4-Hydroxypiperidines
;
Substituent effects
;
gauche interactions
;
13C NMR
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
13C NMR spectra of six epimeric substituted 4-hydroxypiperidines and two corresponding piperidines were recorded. Substituent parameters for equatorial methyl, gem-dimethyl, equatorial hydroxy and axial hydroxy groups were calculated from the 13C chemical shifts of these compounds and several other six-membered ring compounds. The effects of nearby substituents on these parameters were examined. It is concluded that the magnitude and even the sign of the α effect is modified by the presence of nearby substituents. It was found that gauche interactions play an important role in determining the magnitude of the α effect. However, the β effect is not influenced by the nearby substituents except for the gem-dimethyl group. The magnitude of the γ effect is almost independent of the nearby substituents.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260290908
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