6-Methyl-ideneandrost-4-ene-3,17-dione

• Main Author: Andrade, L. C. R.
• Publication Date: 2012
• Other Authors: Almeida, M. J. M., Roleira, F. M. Fernandes, Varela, Carla Lopes, Tavares da Silva, E.J.
• Format: Article
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: https://hdl.handle.net/10316/109825; https://doi.org/10.1107/S1600536812013207
• topic: single-crystal X-ray study; T = 293 K; mean (C–C) = 0.004 A°; R factor = 0.040; wR factor = 0.100; data-to-parameter ratio = 9.8

In the title compound, C(20)H(26)O(2), which is the 6-methyl-ene derivative of androstenedione and a synthetic percursor of exemestane, the steroid A ring approximates to a sofa (or envelope) conformation, with the methyl-ene group adjacent to the link to the B ring lying out of the plane of the other atoms. The B and C rings have slightly flattened chair conformations and the D ring is an envelope, with the CH group forming the flap. In the crystal, mol-ecules are linked by two distinct C-H⋯O hydrogen bonds, involving acidic H atoms close to C=C and C=O double bonds.