In contrast with the general observation that the modified Kishner-Wolff reduction of an a-ketol leads essentially to the elimination of the hydroxy group,the reduction of 17 β-aldehydo-l7α-hydroxy compound(Ⅰ) yields mainly Ⅳ with retention of the hydroxy group,whereas reduction of Ⅵ gives Ⅶ as the principal product.The major product obtained by the same reduction of the a,β-unsaturated ketone(Ⅹ) has been found to be the sidechain saturated compound(ⅩⅠ) instead of the expected compound(Ⅶ).