Crystal and molecular structure of 17α-hydroxyandrost-4-en-3-one (epitestosterone)
Crystals of the title steroid are orthorhombic, a= 11·423(1), b= 20·151(1), c= 7·003(1)Å, Z= 4, space group P212121. The structure has been determined by direct methods from diffractometer data and refined by full-matrix least-squares to a final R of 0·058 for 1646 reflections. All the ring junctions are trans/trans. The conformation of ring A is half-chair while that of rings B and C is chair. The cyclopentane ring D is a slightly distorted half-chair. The molecules are linked in the crystal structure ‘head-to-tail’ by a hydrogen bond between the C(17) hydroxy-group and the C(3) keto-group.