17α-benzyl-17β-hydroxy-16-hydroxyimino-3-methoxyestra-1,3,5(10)-triene

The asymmetric unit of the title compound, 17α-benzyl-16-hydroxyimino-3-methoxyestra-1,3,5(10)-trien -l7β-ol, C 26 H 31 NO 3 , contains two molecules which differ in the orientations of the methoxy groups at C(3). The 17-hydroxy and 16-hydroxyimino moieties are involved in intramolecular N...O and intermolecular N...O and O...O hydrogen bonds. The hydrogen-bond network accounts for the differences in bond and torsion angles of the α-hydroxyimino moieties of the symmetry-independent molecules. This has been confirmed by molecular-mechanics calculations on the individual molecules which indicate that they have the same geometry in their energy minimum states.