| abstract |
7 beta -Acylamino-3-azido-3-cephem-4-carboxylic acid esters are obtained with the corresponding 3-halo or 3-sulfonyloxy-3-cephem esters and an alkali metal azide. The 3-azido compounds as the free acids or salts are antibacterial agents while in esterified form react with alcohols and phenols to provide 2-alkoxy (or 2-phenoxy)-3amino-3-cephem esters and isomeric ring expanded 4,7-bicyclo beta -lactam compounds, namely [2R-(2 alpha ,7 alpha ,8 beta )-4-alkoxy (or 4-phenoxy)-9-oxo-8-acylamino-6-thia-1,3-diazabicyclo[5.2.0]non-3-ene-2 -carboxylic acids and esters and the corresponding 3-alkoxy (or 3-phenoxy) 1,4-diazabicyclo[5.2.0]non-3-ene-2-carboxylic acids and esters. These reaction products obtained with the azide possess antibacterial properties. |