On the Optical Activity of Steroidal 5,7-Dienes
Circular dichroism (CD) data are reported of a series of 9,10- stereoisomeric steroidal 5,7-dienes. In general the effects in the longest wavelength transition (270-280 nm) are large (Mm" 10---30) and consignate with respect to the diene helicity rule. The magnitude of the CD appears to vary ma...
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Published in | Croatica Chemica Acta Vol. 62; no. 2A; p. 115 |
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Main Authors | , , |
Format | Paper |
Language | English |
Published |
Hrvatsko kemijsko društvo
30.06.1989
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Online Access | Get full text |
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Summary: | Circular dichroism (CD) data are reported of a series of 9,10-
stereoisomeric steroidal 5,7-dienes. In general the effects in the
longest wavelength transition (270-280 nm) are large (Mm" 10---30)
and consignate with respect to the diene helicity rule. The magnitude
of the CD appears to vary markedly with the substituent at C-3 and at C-17, and with solvent. In the case of the 9a,10p-H dienes, variation of solvent and temperature can affect even the sign of the Cotton effect. This is explained from a change of geometry of the diene ring: solvation, substitution and temperature can affect the average geometry of the ring including the values of the angle of twist of the diene (ef> (6-7». The relevance of the observed chiroptical data for the theoretical description of the optical activity in the So-+ Sl transition of homoannular cisoid dienes is discussed. |
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Bibliography: | 175386 |
ISSN: | 0011-1643 1334-417X |