Synonyms: 2-Butenoicacid, 2-methyl-,6-(acetyloxy)-2,3,3a,4,5,6,6a,7,8,9b-decahydro-3,3a-dihydroxy-3,6,9-trimethyl-2-oxo-4-(1-oxobutoxy)azuleno[4,5-b]furan-8-ylester, [3S-[3a,3ab,4a,6b,6ab,8a(Z),9ba]]-; Azuleno[4,5-b]furan, 2-butenoic acid deriv.; (-)-Nortrilobolide;Nortrilobolide