Purify 5-androstane by chromatography through Al2O3 (grade III) and elute with pet ether and recrystallise from MeOH (2x) and Me2CO/MeOH. It sublimes at 60o/high vacuum. Also dissolve it in pet ether, filter it through silica gel, evaporate and recrystallise it. [Steiger & Reichstein Helv Chim Acta 20 817 1937, Prelog et al. Helv Chim Acta 27 66 1944, IR, NMR: Halkes & Havinga Rec Trav Chim Pays-Bas 8 4 889 1965, Allinger et al. Tetrahedron 27 5073 1971, Beilstein 5 III 1110, 5 IV 1211.]
