2-Butenoic acid, 2-methyl-, (1R,4R,4aR,5S,6R,8S,8aR)-8-(acetyloxy)-8a-((acetyloxy)methyl)-5-((2S)-2-(2,5-dihydro-5-oxo-3-furanyl)-2-hydroxyethyl)octahydro-5,6-dimethylspiro(naphthalene-1(2H),2'-oxiran)-4-yl ester, (2E)- 78798-40-0