Crystal Structure of 9?,11-Epoxy-7?-(methoxycarbonyl)-3-oxo-17?-pregn-4-ene-21,17-carbolactone.

The title compound (common name eplerenone), C24H30O6, is an aldosterone receptor antagonist. From the isopropyl acetate solution the compound crystallizes in monoclinic space group P 21 with a = 8.811(1) Å, b = 11.250(1) Å, c = 11.079(1) Å, ? = 93.822(12)°, Z = 2. The molecule contains three six membered rings, two five membered rings and one three membered ring. Both five membered rings display envelope conformation, whereas three six membered rings show different conformation: chair, half-chair and envelope. In the crystal the eplerenone molecules link to one another via intermolecular weak C–H···O hydrogen bonding to form the smaller cavity of 12.0(1) Å3 between eplerenone molecules, no solvent molecule filled in this cavity. Index Abstract  In the title molecule three six-membered rings show different conformation. Weak C–H···O hydrogen bonding links adjacent molecules to form the small cavity 12.0(1) Å3, no solvent molecule filled in the cavity. [ABSTRACT FROM AUTHOR]