Synonyms: Hygrolidin,21-de[(3-carboxy-1-oxo-2-propenyl)oxy]-19,23-deepoxy-23-deethyl-20,21-didehydro-2-demethyl-19-deoxy-23-hydroxy-2-methoxy-23-methyl-19-oxo-;Oxacyclohexadecane, hygrolidin deriv.; Oxacyclohexadeca-3,5,11,13-tetraen-2-one,16-(2,8-dihydroxy-1,3,7-trimethyl-4-oxo-5-nonenyl)-8-hydroxy-3,15-dimethoxy-5,7,9,11-tetramethyl-,[7R-[3Z,5E,7R*,8S*,9S*,11E,13E,15S*,16R*(1S*,2R*,3S*,5E,7S*,8R*)]]-; PD 118576