New 4-nitro and 4-amino 5α-steroids were made regioselectively from cholesterol via nitration of 3-acetoxy-5α-cholesta-l,3-diene (2). Nitration of enol acetate (2) gave 4α-nitro-5α-cholest-1-en-3-one (3), which was catalytically reduced to 4α-nitro-5α-cholestan-3-one (4). Sodium borohydride reduction of (4) gave 4α-nitro-5α-cholestan-3β-ol (5). Reduction of 4α-nitro-5α-cholestan-3β-ol with lithium
通过硝化3-乙酰氧基-5α-
胆甾醇-1,3-二烯(2),由
胆固醇区域选择性地制备出新的4-硝基和4-
氨基5α-类
固醇(2)。
硝酸烯醇
乙酸酯(2)的硝化得到4α-硝基-5α-胆甾烯-1-烯-3-酮(3),其被催化还原为4α-硝基-5α-
胆甾醇-3-烯酮(4)。(4)的
硼氢化钠还原得到4α-硝基-5α-
胆甾醇-3β-醇(5)。用
氢化铝锂还原得到的4α-硝基5α-
胆甾醇3β-醇(4-
氨基-3,4-seco-5α-
胆甾醇3β-ol(6)而不是所需的4α-
氨基5α-
胆甾醇-3β-ol(8)。化合物的合成(8)需要事先将4α-硝基
甾醇衍生为3-(
四氢吡喃-2-基)醚。经由4α-甲酰基中间体也已经合成了相关的4α-
氨基甲基-5α-
胆甾醇-3β-醇(12)。