ISSN:
0749-1581
Schlagwort(e):
3,4-Dihydro-2H-1,3-benzoxazines
;
13C NMR spectroscopy
;
Substituent effects
;
Stereochemistry
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Seventeen N-substituted 3,4-dihydro-2H-1,3-benzoxazines [N-substituent = Et, Pri, But, CH2C6H5 or CH(CH3)C6H5] were prepared and their structures studied in the light of 13C chemical shifts. The γ effects caused by C(α)-methyl or C(α)-phenyl substitution at the heterocyclic ring carbons were found to be valuable structural parameters. By using N-tert-butyl derivatives as models, and by dividing γtot effects into their components, the rotamer populations due to the rotation around the N—C(α) bond could be evaluated. The method also allows the configurational assignment of diastereomeric N-α-methylbenzyl derivatives. The effect of the half-chair structure on the 13C NMR parameters is discussed.
Zusätzliches Material:
1 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/mrc.1260280309
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