4-Thia-1-azabicyclo(3.2.0)heptane-2-carboxylic acid, 3,3-dimethyl-7-oxo-6-((1-oxo-2-phenoxybutyl)amino)-,monopotassium salt, (2S-(2alpha,5alpha,6beta(R*)))-; 4803-44-5 Levopropylcillin potassium Levopropylcillin potassium [USAN]