(2R)-6-methyl-4-oxo-3,5-dioxaheptan-2-yl (2R)-2-[(3Z,7R)-8-({4-[(3Z)-5-{[(7aR,7R)-4-[(3R)-3,7-dimethyl-1,5-dioxo-2,4,6-trioxaoct-1-yl]-3-(methoxymethyl)-6-oxo-2,6,7,7a-tetrahydroazeto[2,1-b][1,3]thiazin-7-yl]amino}-5-oxo-3-aza-2-oxapent-3-en-4-yl]-1,3-thiazol-2-yl}amino)-4-(2-amino-1,3-thiazol-4-yl)-5,8-dioxo-3,6-diaza-2-oxaoct-3-en-7-yl]-5-(methoxymethyl)-3H,2H,6H-1,3-thiazine-4-carboxylate