The crystal and molecular structure of d1-17β-hydroxy-8α-androst-4-en-3-one (8-isotestosterone)

The molecular conformation of d1̲-8-isotestosterone has been determined crystallographically. Crystals of the title compound belong to the space group P21/c with a̲ = 11.449(4), b̲ = 10.962(4), c̲ = 25.860(5) , β = 100.95(4)0, with two molecules in the asymmetric unit. The structure has been refined to a final R value of 0.052 for 2227 reflections. Unlike testosterone, which is a flat molecule, its 8-isomer has a folded conformation. The conformations of the ring-B in the two crystallographically independent molecules (A and B) correspond to the twist form and differ significantly from one another