4-Thia-1-azabicyclo(3.2.0)hept-2-ene-2-carboxylic acid, 3-(((aminocarbonyl)oxy)methyl)-6-(1-hydroxyethyl)-7-oxo-, (acetyloxy)methyl ester, (5R-(5-alpha,6-beta(R*)))- 99376-22-4 RIPM-AC Ritipenem Acoxil Ritipenem acetoxymethyl ester