YLT ylt (1'S,3aS,5R,16R,17S,19E,21S,21aR)-6'-chloro-21-methoxy-16,17-dimethyl-2,3,3',3a,4',16,17,18,21,21a-decahydro-2'H,6H,8H-15lambda~6~-spiro[10,12-etheno-15lambda~6~-furo[3,2-i][1,4]oxazepino[3,4-f][1,2,7]thiadiazacyclohexadecine-7,1'-naphthalene]-13,15,15(4H,14H)-trione YLT