Conformational analysis of colchicinoids containing an electron-deficient aromatic ring on the B ring

Autor:	Erica A. Pyles, Susan Bane Hastie
Rok vydání:	1993
Předmět:	Steric effects chemistry.chemical_compound Atropisomer chemistry Stereochemistry Organic Chemistry Substituent Proton NMR Electronic effect Nuclear Overhauser effect Nuclear magnetic resonance spectroscopy Ring (chemistry)
Zdroj:	The Journal of Organic Chemistry. 58:2751-2759
ISSN:	1520-6904 0022-3263
Popis:	A dinitrophenyl substituent at the C-7 position of N-deacetylcolchicine and N-deacetylisocolchicine was shown to perturb the 1 H NMR and circular dichroic spectra of colchicinoid ring systems. The perturbations were explained by an interaction between the C-7 substituent and the A and/or C rings. Other aromatic substituents or large substituents located at the C-7 position (J. Med. Chem. 1983, 26, 1365) have not been reported to influence the aS-aR equilibrium of the phenyltropone ring junction. It was concluded that the sterically unfavored atropisomers were stabilized by the interaction of an electron-deficient ring with the more electron-rich A ring of the colchicinoid molecules
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::dd8aebf158e9592631789e5684c1423d https://doi.org/10.1021/jo00062a016 Zobrazit plný text záznamu