| 摘要 |
Disclosed are 6- and 4-substituted-1-azabicyclo[3.2.0]heptan-3,7-dione-2-carboxylic acid esters and salts (I) which are useful in the preparation of 6-, 1- and 2-substituted carbapenem antibiotics. <IMAGE> I wherein R5 is a pharmaceutically acceptable ester moiety or a removable protecting group or an alkali or alkaline earth metal cation such as sodium or potassium and wherein R1, R2, R3 and R4 are, inter alia, independently selected from the group consisting of hydrogen, alkyl, aryl and aralkyl. |
