Structure of 9α, 11β-dichloro-4-pregnene-3,20-dione, C21H28O2Cl2

Abstract

The crystal and molecular structure of 9α, 11β-dichloro-4-pregnene-3,20-dione, C21H28O2C12, has been determined:Mr=383.4,P31,a=7.358(2),c=30.137(20) A,Vc=1413(2)A3,Z=3,Dx=1.35 g cm−3, λ(MoKα)=0.71073A,μ=3.6 cm−1,F(000)=612,T≈80K,R=0.060,Rw=0.052 for 2376 unique observed reflections. The steroid skeleton exhibits a flattening of theA ring relative to the rest of the molecule caused by halogen substituents. The title compound has a very high relative binding affinity for the rabbit uterine progesterone receptor. The high binding affinity may result from the flattening of theA ring relative to the rest of the steroid skeleton.