6- and 4-Substituted-1-azabicyclo[3.2.0]heptan-3,7-dione-2-carboxylates

A compound having the structure:

• ##STR101## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently selected from the group consisting of hydrogen, (R.sup.1 and R.sup.2 are not both hydrogen), substituted and unsubstituted:
• alkyl, alkenyl, and alkynyl, having from 1-10 carbon atoms;
• cycloalkyl, cycloalkylalkyl, and alkylcycloalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in the alkyl moieties;
• spirocycloalkyl having 3-6 carbon atoms;
• phenyl;
• aralkyl, aralkenyl, and aralkynyl wherein the aryl moiety is phenyl and the alkyl chain has 1-6 carbon atoms;
• wherein the substituent or substituents relative to the above-named radicals are selected from the group consisting of:
• amino, mono-, di-, and trialkylamino, hydroxyl, alkoxyl, mercapto, alkylthio, phenylthio, sulfamoyl, amidino, guanidino, nitro, chloro, bromo, fluoro, iodo, cyano, and carboxy;
• and wherein the alkyl moieties of the above-recited substituents have 1-6 carbon atoms;
• R.sup.5 is hydrogen, salt cation, a pharmaceutically acceptable ester moiety or a removable blocking group.