Azetidine-2,3-diones (α-oxo-β-lactams) and bromonitromethane undergo coupling in aqueous media in the presence of catalytic amounts of sodium azide. The stereoselectivity of the process was generally good, proceeding with reasonable anti : syn ratios under substrate control. On this basis, a simple and fast protocol for the synthesis of the potentially bioactive 3-substituted 3-hydroxy-β-lactam moiety has been developed. Besides, 2-azetidinone-tethered 1-halo-1-nitroalkan-2-ols are quite useful building blocks; for example, reactions of the above nitrobromohydrins provided spiranic and fused bicyclic-β-lactams.
乙基丁二酸二酮(α-氧代-β-内酰胺)和
溴硝基甲烷在催化量的
叠氮化
钠存在下,在
水介质中发生偶联反应。该过程的立体选择性通常良好,在底物控制下能获得合理的反式:顺式比率。基于此,我们开发了一种简便快捷的方法来合成潜在
生物活性的3-取代-3-羟基-β-内酰胺片段。此外,2-吖丁啶酮连接的1-卤代-1-硝基烷-2-醇是非常有用的构建单元;例如,上述
硝基溴氢醇的反应提供了螺旋内酰胺和稠合双环-β-内酰胺。