Dioximes of Cortisol,Stereoisomer Identification by Carbon-13 Nuclear Magnetic Resonance |
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| Authors: | Nancy Khouri Alfredo Usubillaga Jaime N. Delgado |
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| Affiliation: | 1. Instituto de Investigaciones, Facultad de Farmacia , Universidad de los Andes , Merida, 5101, Venezuela;2. Department of Medicinal Chemistry , College of Pharmacy University of Texas at Austin , Austin, Texas, 78712-1074, U.S.A. |
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| Abstract: | Treatment of cortisol with hydroxylamine hydrochloride yields mainly two dioximes, the EE and ZE stereoisomers. In the EE isomer, the hydroxyl at C-3 oxime, is oriented towards C-2 causing a large upfield shift on this carbon which is attributed to steric compression caused by the hydroxyl. In the ZE isomer, the hydroxyl points toward C-4. Here, steric compression affects carbons C-4 to C-6 causing a diamagnetic shift. The oxime at C-20 assumes only the E-configuration because of steric hydrance. |
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| Keywords: | dioximes of Cortisol EE and ZE isomers 13C-NMR |
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