抄録
The β-axial hydroxylated 5β-spirostan-1- and 3-ones were prepared from the steroidal sapogenins in Convallaria and diosgenin, and the optical rotatory dispersion curves of these ketones were measured in methanol or dioxane. The 5-hydroxy-25 (R), 5β-spirostan-3-one (XIII) showed a weak positive amplitude (a : +16.0) in contrast to the negative one of the parent 3-ketone (I, a : -16.6). The hydroxyl groups substituted on the symmetrical β-axial positions to the carbonyl groups led to marked changes in the amplitude of Cotton effect in the 5β-spirostanones, and opposed to the prediction from the octant rule.
