title: Methyl 2-(3a,8a-dimethyl-4-oxodeca-hydro-azulen-6-yl)acrylate.
abstract: The title compound, C(16)H(24)O(3), was synthesized from ilicic acid, which was isolated from the aerial part of Inula viscosa- (L) Aiton [or Dittrichia viscosa- (L) Greuter]. The asymmetric unit contains two independent mol-ecules, in each of which the seven-membered ring shows a chair conformation, whereas the five-membered ring presents disorder. In the two molecules, three C atoms in the five-membered ring are disordered over two positions with site-occupancy factors of 0.53/0.47 and 0.83/0.17. The dihedral angle between the two rings is different in the two mol-ecules [31.7 (3) and 47.7 (7)°]. The crystal structure is stabilized by weak inter-molecular C-H⋯O hydrogen-bond inter-actions.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Tebbaa
authors.forename: Ahmed
authors.initials: A
authors.lastname: Benharref
authors.forename: Moha
authors.initials: M
authors.lastname: Berraho
authors.forename: Jean Claude
authors.initials: JC
authors.lastname: Daran
authors.forename: Mohamed
authors.initials: M
authors.lastname: Akssira
authors.forename: Ahmed
authors.initials: A
authors.lastname: Elhakmaoui
references.citation: J Med Chem. 1970 Nov;13(6):1221-3
references.pmid: 5479871
references.citation: Planta Med. 1982 Mar;44(3):159-61
references.pmid: 17402102
references.citation: J Nat Prod. 1988 Sep;51(5):1006-9
references.pmid: 21401196
references.citation: Acta Crystallogr D Biol Crystallogr. 2009 Feb;65(Pt 2):148-55
references.pmid: 19171970
references.citation: Pharm Acta Helv. 1986;61(12):345-52
references.pmid: 3809210
references.citation: Acta Crystallogr A. 2008 Jan;64(Pt 1):112-22
references.pmid: 18156677