Acid cleavage of β-epoxide (IX) gave ba-methyl cholestan-3β, 5a, 6β-triol (VⅡa) identical with that obtained by treatment of 3β-acetoxy-5a-hydroxy-cholestan-6one (VIb) with methyl magnesium iodide.Elimination of 5a-hydroxy of compound X with alkali gave XI which is the isomer of XⅢ obtained from XⅡ by treatment with alkali.These results confirm the conclusion of Fieser^[2], Shiota^[4] that Grignard reaction of 6-oxo-5a-steroid involves the least hindered a-attack by the reagent.