(3'S,4'S,7a'R,7'R)-7'-{[(3E)-4-(2-amino-1,3-thiazol-4-yl)-5-oxo-3-aza-2-oxapent-3-en-5-yl]amino}-9-methyl-6',7,8-trioxo-4',6',7',7a'-tetrahydro-2'H-spiro[4-thia-1,6,9-triazabicyclo[3.3.1]non-5(6)-ene-2,3'-azeto[2,1-b][1,3]thiazine]-4'-carboxylic acid