CONFORMATIONAL-ANALYSIS OF AN OPTICALLY-ACTIVE BILIRUBIN DIMETHYL ESTER AND BIS-N,N-DIMETHYL AMIDE BY CIRCULAR-DICHROISM, NMR AND MOLECULAR-DYNAMICS

Authors
BOIADJIEV SE ANSTINE DT LIGHTNER DA
Citation
Se. Boiadjiev et al., CONFORMATIONAL-ANALYSIS OF AN OPTICALLY-ACTIVE BILIRUBIN DIMETHYL ESTER AND BIS-N,N-DIMETHYL AMIDE BY CIRCULAR-DICHROISM, NMR AND MOLECULAR-DYNAMICS, Tetrahedron : asymmetry, 5(10), 1994, pp. 1945-1964
Citations number
30
Categorie Soggetti
Chemistry Inorganic & Nuclear","Chemistry Inorganic & Nuclear","Chemistry Physical
Journal title
Tetrahedron : asymmetry → ACNP
ISSN journal
09574166
Volume
5
Issue
10
Year of publication
1994
Pages
1945 - 1964
Database
ISI
SICI code
0957-4166(1994)5:10<1945:COAOBD>2.0.ZU;2-5
Abstract
The dimethyl ester and bis-N,N-dimethylamide of an optically active an alog of bilirubin (beta S,beta'S-dimethylmesobilirubin-XIII alpha) is stabilized in a ridge-tile conformation by intramolecular hydrogen bon ding, as detected by H-1-NMR and CD spectroscopy. The ridge-tile shape is most evident in nonpolar solvents, where very strong exciton coupl ing CD is evident: e.g., in benzene, Delta epsilon(412)(max) -199, Del ta epsilon(372)(max)+87 for the dimethyl ester and Delta epsilon(421)( max)-165, Delta epsilon(384)(max)+46 for the bis-N,N-dimethylamide.