Structure of 11α-hydroxy-progesterone, C₂₁H₃₀O₃

The structure of the title compound, C₂₁H₃₀O₃, was determined by X-rays. M_r=330.5, orthorhombic, P2₁2₁2₁, a=8.4451(9), b=10.7074(8), c=20.1525(40) Å, V=1822(8) ų, Z=4, D_x=1.205 mg m^-3. Cu Kα radiation (1.54184 Å), μ(Cu Kα)=5.85 cm^-1, F(000)=720. Final R=0.054 R_w=0.049 for 1774 unique reflections. The structure was solved using Multan. The A ring adopts an intermediate sofa-half-chair conformation and is bent toward the α face of the steroid skeleton. Rings B and C have typical chair conformations, and the D ring has a slightly distorted half-chair conformation. The progesterone side chain has a typical conformation, and the C16-C17-C20-O20 torsion angle is -17.9°. An intermolecular hydrogen bond is formed between the hydroxyl group and the progesterone side chain.