Steroids XXVII

There are four theoretically possible stereoisomers of cholestane-33, 5, 6-triol (I) -(IV) with respect to the configurations at C( 5) and C(6), and three of them (I) -(III) have already been described.Among others, cholestane-3a, 5a, 69-triol (a-cholestanetriol) (I) may be obtained easily in several ways.The syntheses of the second triol cholestane-3a, 5a, 6a-triol (R-cholestanetriol) (II), heretofore are known in four different ways.All these methods, however, are not convenient ) -)