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-alpha(R*)))- 87238-52-6 ACETOXYMETHYL(5R,6S)-2-CARBAMOYLOXYMETHYL-6-((1R)-HYDROXYETHYL)-2-PENEM-3-CARBOX Acetoxymethyl (5R,6S)-2-carbamoyloxymethyl-6-((1R)-hydroxyethyl)-2-penem-3-carboxylate BRN 4723315 Fce 22891 Ritipenem acetoxymethyl ester