3,3-Dimethyl-7-oxo-6-[(phenoxyacetyl)amino]-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid
3,3-dimethyl-7-oxo-6-[(1-oxo-2-phenoxyethyl)amino]-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid is a penicillin.