2-Butenoic acid, 2-methyl-, (3S,3aR,4S,6S,6aS,9aS,9bS)-2,3,3a,4,5,6,6a,7,9a,9b-decahydro-6-hydroxy-3,6,9-trimethyl-2-oxoazuleno(4,5-b)furan-3,4-diyl ester, (2Z,2'Z)- 68852-48-2