Pure 14α and 14β epimers of Δ8-11-keto steroids with different 17β-alkyl groups were prepared and the position of their base-catalyzed equilibrium established by gas-liquid phase chromatography. In contrast to 15-keto steroids, where the nature of the 17β substituents crucially affects the cis/trans hydrindanone equilibrium, the 14β (C/D cis) isomer is greatly favored in the present series irrespective of the nature of the C-17 substituent. Using a previously described force-field method, the energies and conformations of the cis and trans isomers of the Δ8-11-keto steroids were calculated and found to be in reasonable agreement with the experimentally established values.
All Science Journal Classification (ASJC) codes
- Organic Chemistry