The chemistry of penicillanic acids. Part II. Some reactions of methyl penicillanate and its 6α-bromo- and 6,6-dibromo-derivatives

Abstract

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.