128-21-2 3.beta.-Hydroxy-5.beta.-tetrahydroprogesterone 5.beta.-Pregnan-20-one, 3.beta.-hydroxy- 5.beta.-Pregnanolone Epipregnanolone NSC21450 Pregnan-20-one, 3-hydroxy-, (3.beta.,5.beta.)- Pregnan-3.beta.-ol-20-one Pregnanolone I