| 摘要 |
<p>The preparation of a penam derivative of formula (I): < IMG > (I) wherein RA is hydrogen or a group of formula (Ia): < IMG > (Ia) wherein X is -C02R1, or S03R1; R is C1-6 alkyl, aryl, or heterocyclyl; R1 is hydrogen, or a pharmaceutically acceptable salt-forming ion or ester-forming radical, and R2 represents hydrogen or a pharmaceutically acceptable salt-forming ion or in vivo hydrolyscable ester-forming radical; which process comprises reacting a compound of formula (II): < IMG > (II) wherein RB is a removable acyl group which protects the amino function or a group of formula (IIa): < IMG > (IIa) wherein Y is -C02RX or -S03RX; n is one and m is zero or one; R is as defined with respect to formula (I) above and wherein any reactive groups may he protected; Rx represents an ester-forming radical, RY represents hydrogen, a salt-forming radical or a carboxyl-blocking group, and R3 represents an alkyl, benzyl, or aryl group; with methanol</p> |
