ISSN:
0749-1581
Keywords:
6α,14α-Ethenoisomorphinan
;
6β,14β-Ethenomorphinan
;
Nitrogen anisotropy
;
Face selectivity of the Diels-Alder reaction
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The 1H NMR and 13C NMR spectra of N-formylated morphinans were compared with those of the N-methyl and N-demethyl analogues. The magnitude of the changes in chemical shift of C-9, C-16 and C-10 depended crucially on the nature of the substituent at nitrogen. For the 6α, 14α-ethenoisomorphinans and 6β,14β-ethenomorphinans, the proton chemical shifts of the 6,14-etheno bridge across ring C are differently affected by the nitrogen atom. In the 6α,14α-ethenoisomorphinans, the vinylic proton shifts are found between δ5.3 and 5.9, whereas in the 6β,14β-ethenomorphinans these proton signals are found downfield from δ6.0. A similar, but opposite, anisotropy effect of the nitrogen is observed for the 8β-proton. These results are important for the elucidation of the structures of these types of compounds.
Additional Material:
6 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260271014
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