The action of methyl iodide and strong anhydrous base on methyl penicillanate or its 6α-bromo-derivative leads to S-methylation and cleavage of both thiazolidine and β-lactam rings, but with methyl 6,6-dibromopenicillanate the β-lactam system remains intact. Some further reactions of the resulting (4R)-3,3-dibromo-1-(1-methoxycarbonyl-2-methylprop-1-enyl)-4-methylthioazetidin-2-one are described.
甲基
碘和强的无
水碱基对
青霉酸甲酯或其6α-
溴衍
生物的作用导致
噻唑烷和β-内酰胺环均发生S-甲基化和裂解,但在6,6-二
溴泛酸硅酸甲酯的情况下,β-内酰胺系统保持完好无损。 。描述了所得(4 R)-3,3-二
溴-1-(1-甲氧基羰基-2-甲基丙-1-烯基)-4-甲基
硫氮杂
环丁烷-2-one的一些进一步反应。