1-acetoxyethyl 1-{[(3E)-4-(2-furyl)-3-aza-2-oxahexa-3,5-dien-5-yl]amino}-5-({[(7-{[(3Z)-4-(2-furyl)-5-oxo-3-aza-2-oxapent-3-en-5-yl]amino}-3-[(carbamoyloxidanyl)methyl]-6-oxo-2,6,7,7a-tetrahydroazeto[2,1-b][1,3]thiazin-4-yl)carbonyl]oxy}methyl)-2-oxo-2,6,7,7a-tetrahydro-1H-azeto[1,2-a]pyridine-4-carboxylate