CAS No 88979-61-7 , 2-Butenedioic acid(2E)-,1-[(2R,4R,5S,6R)-tetrahydro-2-hydroxy-2-[(1S,2R,3S)-2-hydroxy-3-[(2R,3S,4E,6E,9S,10S,11R,12E,14Z)-10-hydroxy-3,15-dimethoxy-7,9,11,13-tetramethyl-16-oxooxacyclohexadeca-4,6,12,14-tetraen-2-yl]-1-methylbutyl]-5-methyl-6-(1-methylethyl)-2H-pyran-4-yl]ester