Synonyms: 4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylicacid, 3,3-dimethyl-7-oxo-6-(2-phenoxy-2-phenylacetamido)-, monopotassium salt(8CI); 4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid,3,3-dimethyl-7-oxo-6-(2-phenoxy-2-phenylacetamido)-, potassium salt (7CI); 4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylicacid, 3,3-dimethyl-7-oxo-6-[(phenoxyphenylacetyl)amino]-, monopotassium salt,(2S,5R,6R)- (9CI); 4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid,3,3-dimethyl-7-oxo-6-[(phenoxyphenylacetyl)amino]-, monopotassium salt, [2S-(2a,5a,6b)]-; 6-(a-Phenoxyphenylacetamido)penicillanicacid, potassium salt; Fenbenicillin potassium salt; Penspek