Structure cristalline et moléculaire de la 11-desoxycorticostérone, C₂₁H₃₀O₃

The crystal and molecular structure of 21-hydroxy-4-pregnen-3,20-dione (C₂₁H₃₀O₃) has been determined by single-crystal X-ray diffraction analysis. The crystals are monoclinic, space group P2₁, with a = 8.718, b = 12.509 and c = 8.481 Å, Z = 2. The structure was solved by direct methods. The parameters were refined by a block-diagonal least-squares method with 1563 observed intensities collected with a Hilger–Watts diffractometer. The hydrogen atoms were included in the refinement. The final R value is 0.042. The interatomic distances and bond angles are in good agreement with previously published values. Torsional angle C(16)–C(17)–C(20)–O(20) is equal to −11.2° and O(20)–C(20)–C(21)–O(21) 3.6°. Cohesion of the crystal is due to van der Waals interactions.