N-tert-Butyl-3-hydroxy-5-androstene-17-carboxamide monohydrate

In the title compound, C24H39NO2 center dot H2O, the A and C rings of the pregnolene derivative sterol adopt chair conformations, with the B ring in a flattened chair conformation and the five-membered ring in an envelope conformation twisted about the C/D ring junction. The N-tert-butylcarboxamide substituent is equatorial. The 3 beta-hydroxy H atom and one H atom of the water molecule are disordered over two positions with equal occupancies. In the crystal structure, O-H center dot center dot center dot O hydrogen bonds between the 3 beta-hydroxy groups of neighbouring molecules form dimers in the bc plane and these dimers are stacked along the a axis by additional O-H center dot center dot center dot O hydrogen bonds involving the water molecules. The steric effect of the bulky tert-butyl substituent in the carboxamide chain precludes hydrogen-bond formation by the N-H group.