(2Z,4S,4aS,6S,8aS)-2-[amino(hydroxy)methylidene]-6-[(1S)-7-chloro-4-hydroxy-1-methyl-3-oxo-1,3-dihydro-2-benzofuran-1-yl]-4-(dimethylamino)-8a-hydroxytetrahydronaphthalene-1,3,8(2H,4H,5H)-trione