Reduction of the 11-keto to the 11β-hydroxyl group in the 16α-methylated allopregnanes II and VIIIb has been accomplished. In the case of the 20-enol acetate II, sodium borohydride was used, whereas in the case of the 11,20-diketone VIIIb, prepared in a conventional manner from II, selective catalytic hydrogenation was employed.
在16α-甲基化的四氢
异戊二烯II和VIIIb中,已经完成了将11-酮还原为11β-羟基的操作。在20-烯醇
乙酸酯II的情况下,使用
硼氢化钠,而在以常规方式由II制备的11,20-二酮VIIIb的情况下,使用选择性催化氢化。