title: Crystal structure of pseudoguainolide.
abstract: The lactone ring in the title mol-ecule, C15H22O3 (systematic name: 3,4a,8-tri-methyl-dodeca-hydro-azuleno[6,5-b]furan-2,5-dione), assumes an envelope conformation with the methine C atom adjacent to the the methine C atom carrying the methyl substituent being the flap atom. The other five-membered ring adopts a twisted conformation with the twist being about the methine-methyl-ene C-C bond. The seven-membered ring is based on a twisted boat conformation. No specific inter-actions are noted in the the crystal packing.
authors.affiliation: Unité de Recherche VARENBIOMOL, Constantine 1 University, Constantine 25000, Algeria.
authors.forename: Noureddine
authors.initials: N
authors.lastname: Beghidja
authors.affiliation: Unité de Recherche VARENBIOMOL, Constantine 1 University, Constantine 25000, Algeria.
authors.forename: Samir
authors.initials: S
authors.lastname: Benayache
authors.affiliation: Unité de Recherche VARENBIOMOL, Constantine 1 University, Constantine 25000, Algeria.
authors.forename: Fadila
authors.initials: F
authors.lastname: Benayache
authors.affiliation: School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, Wales.
authors.forename: David W
authors.initials: DW
authors.lastname: Knight
authors.affiliation: School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, Wales.
authors.forename: Benson M
authors.initials: BM
authors.lastname: Kariuki
keywords: crystal structure; inula graveolens; plant extract
references.citation: Acta Crystallogr A. 2008 Jan;64(Pt 1):112-22
references.pmid: 18156677
references.citation: Phytochemistry. 2012 Apr;76:133-40
references.pmid: 22277736