2-Butenoic acid, 2-methyl-, 2,3,3a,4,4a,5,6,7,9,9a-decahydro-5-hydroxy-3,5,8-trimethyl-2,9-dioxoazuleno(6,5-b)furan-6-yl ester, (3S-(3alpha,3abeta,4abeta,5beta,6beta(E),9abeta))- 79236-43-4