Molecular structure of 3β-acetoxypregn-5-en-20-ol 20-methoxyhemisuccinate

The x-ray crystal structure of a steroid hormone-3β-acetoxypregn-5-en-20-ol 20-methoxy- hemisuccinate C28H42O6--was determined. The asymmetric unit of the crystal contains two molecules. The parameters of the triclinic unit cell are: a=18.050(5), b=11.435(2), and c=6.673(1) A; α=91.19(1) deg., β=100.09(1) deg., and γ=83.95(1) deg.; V=1348.5(6) A 3; sp. gr. P1; and Z=2. The least-squares refinement for 2121 unique reflections with I≥3σ(I) led to the final R=0.059. The 17β side chains of the molecules have trans orientations relative to the C(16)-C(17) bonds and are rather mobile. The O(23) and O(26) carbonyl atoms are mutually quasi-trans allowing easy access to the active molecular sites on a steroid-receptor interaction