N-((R)-2-(((5aR,6R)-1,7-dioxo-1,3,4,5a,6,7-hexahydroazeto[2,1-b]furo[3,4-d][1,3]thiazin-6-yl)amino)-1-(4-hydroxyphenyl)-2-oxoethyl)-4-ethyl-2,3-dioxopiperazine-1-carboxamide; Des-(N-methyl-5-tetrazolethiolyl)furolactone Cefoperazone; [5aR-[5a?,6?(R*)]]-4-Ethyl-N-[1-(4-hydroxyphenyl)-2-oxo-2-[(1,4,5a,6-tetrahydro-1,7-dioxo-3H,7H-azeto[2,1-b]furo[3,4-d][1,3]thiazin-6-yl)amino]ethyl]-2,3-dioxo-1-piperazinecarboxamide; BP Cefoperazone Sodium Impurity A; Cefoperazone EP Impurity A
