Synonyms: Acetamide,N-(2-isopropylidene-3,7-dioxo-4-thia-1-azabicyclo[3.2.0]hept-6-yl)-2-phenyl-(7CI,8CI); Benzeneacetamide,N-[2-(1-methylethylidene)-3,7-dioxo-4-thia-1-azabicyclo[3.2.0]hept-6-yl]-,(5R-trans)-; 4-Thia-1-azabicyclo[3.2.0]heptane-3,7-dione,2-isopropylidene-6-(2-phenylacetamido)-; Anhydropenicillin G; Penicillin G,anhydro-