2-Butenoic acid, 2-methyl-, (1aR,3S,4Z,5aR,8aR,9R,10aR)-3-(acetyloxy)-1a,2,3,5a,7,8,8a,9,10,10a-decahydro-4,10a-dimethyl-8-methylene-7-oxooxireno(5,6)cyclodeca(1,2-b)furan-9-yl ester, (2Z)- 73522-57-3