title: (-)-kolavenic Acid.
abstract: In the two, almost identical, mol-ecules in the asymmetric unit of the title compound [systematic name: (E)-3-methyl-5-(1,2,4a,5-tetra-methyl-1,2,3,4,4a,7,8,8a-octa-hydro-naphthalen-1-yl)pent-2-enoic acid], C(20)H(32)O(2), the rings are trans fused. The cyclo-hexane ring has a chair conformation and the cyclo-hexene ring a distorted half-boat conformation. The two independent mol-ecules are connected into a dimer via O-H⋯O hydrogen bonds. The dimers are associated into supra-molecular chains along c via C-H⋯O contacts.
authors.forename: Julio
authors.initials: J
authors.lastname: Zukerman-Schpector
authors.forename: Lucas
authors.initials: L
authors.lastname: Sousa Madureira
authors.forename: Gisele B
authors.initials: GB
authors.lastname: Messiano
authors.forename: Lucia M X
authors.initials: LM
authors.lastname: Lopes
authors.forename: Edward R T
authors.initials: ER
authors.lastname: Tiekink