Treatment of 3-oxo-5β-steroids with diacetoxyiodobenzene/KOH triggered a fast and regioselective Favorskii rearrangement that exclusively led to 3β-methoxycarbonyl-5β-4-norsteroids in good yields. The outcome of the reaction indicates that although both Cyclopropanone and Semi-benzylic pathways are possible, in the case of 3-oxo-5β-steroids, only the last participates. Unambiguous characterization
用
二乙酰氧基
碘苯/KOH 处理 3-oxo-5β-类
固醇引发了快速且区域选择性的 Favorskii 重排,该重排专门导致 3β-甲氧羰基-5β-4-norsteroids 的产率很高。反应结果表明,虽然环
丙酮和半苄基途径都是可能的,但在 3-oxo-5β-类
固醇的情况下,只有最后一个参与。产物的明确表征通过核磁共振和 X 射线衍射研究实现。