2-Butenoic acid, 2-methyl-, 6-(acetyloxy)-2,3,3a,4,5,6,6a,7,8,9b-decahydro-3,3a-dihydroxy-3,6,9-trimethyl-4-(2-methyl-1-oxobutoxy)-7-(3-methyl-1-oxobutoxy)-2-oxoazuleno(4,5-b)furan-8-yl ester 81127-21-1