Structure of 6-methyl-3,20-dioxo-4,6-pregnadien-17α-yl acetate, C₂₄H₃₂O₄

The X-ray structure of 6-methyl-3,20-dioxo-4,6-pregnadien-17 α-yl acetate is reported. The crystals are monoclinic, space group P2₁, Z=4, a=28.955(7), b=6.597(2), c=11.064(3) Å, /gb=90.80(2) °. The two crystallographically independent molecules have very similar overall geometries. The A rings have intermediate sofa-half-chair conformations and are bent relative to the steroid skeleton. The conformation of the 17 β-progesterone side chain is stabilized by the 17 α-ester substituent; the C(16)-C(17)-C(20)-O(20) torsion angle is -19.4(6) and -20.6(7)°.