Crystal and molecular structure of 17β-hydroxyandrost-4-en-3-one (testosterone)

Anhydrous testosterone is monoclinic, space group P21, a= 14·720(3), b= 11·080(2), c= 10·868(2)Å, β= 113·34(1)°, Z= 4. The structure was solved from diffractometer data by direct methods and refined to R 0·038 for 2498 observed (of a total of 2749) reflexions. The two independent molecules in the asymmetric unit have significantly different conformations. This finding is discussed in conjunction with results from studies on epitestosterone and two hydrated forms of testosterone in terms of the relationships between molecular structure and biological activity.