Catalytic Approaches to the Synthesis of β-Lactamase Inhibitors

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• 作者：Buynak ; John D. ; Doppalapudi ; Venkata Ramana ; Frotan ; Mohammed ; Kumar ; Ramon ; Chambers ; Alison
• 关键词：tin and compounds ; cephalosporins ; penicillins ; enzyme inhibitors
• 刊名：Tetrahedron
• 出版年：2000
• 出版时间：July 28, 2000
• 年：2000
• 卷：56
• 期：31
• 页码：5709-5718
• 全文大小：185 K

文摘

Catalytic couplings were utilized to stereospecifically synthesize several 7E- and 7Z-alkylidenecephalosporins. Members of this class are known inhibitors of β-lactamase. Zinc/NH₄Cl reduction of dibromide 14 stereospecifically produced E-monobromide, 15. In contrast, treatment of 14 with isopropylmagnesium bromide, followed by mild acid, stereospecifically produced Z-monobromide 27. These reactions involve stable, intermediate α-(metalloalkylidene)-β-lactams. Monobromides 15 and 27 were stereospecifically coupled to organostannanes, or were converted to the corresponding organostannanes, 22 and 32, which coupled with organohalides.