Synonyms: Ambros-2-en-12-oicacid, 6a,8b-dihydroxy-4-oxo-, 12,8-lactone, (11S)- (8CI);Azuleno[6,5-b]furan-2,5-dione,3,3a,4,4a,7a,8,9,9a-octahydro-4-hydroxy-3,4a,8-trimethyl-, [3S-(3a,3ab,4b,4aa,7ab,8b,9ab)]-; 11,13-Dihydrohelenalin;Dihydrohelenalin; Plenolin