(2,3)-alpha-Methylenebenzylpenicillin 110220-97-8 2,3-Methylene penam 2,3-alpha-Methylenepenam 5-Thia-1-azatricyclo(4.2.0.0(2,4))octane-2-carboxylic acid, 4-methyl-8-oxo-7-((phenylacetyl)amino)-, (2R-(2alpha,4alpha,6beta,7alpha))- Ro 23-6829 Ro-23-6829 alpha-2,3-Methylenepenicillin G