Synonyms: 4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylicacid,6-[[(2R)-[[(4-ethyl-2,3-dioxo-1-piperazinyl)carbonyl]amino]phenylacetyl]amino]-3,3-dimethyl-7-oxo-,(2S,5R,6R)- (9CI);4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid,6-[[[[(4-ethyl-2,3-dioxo-1-piperazinyl)carbonyl]amino]phenylacetyl]amino]-3,3-dimethyl-7-oxo-,[2S-[2a,5a,6b(S*)]]-;Piperacillin;