title: A pregeijerene isomer from Juniperus erectopatens foliage.
abstract: A hydrocarbon that is widespread in Juniperus foliage was isolated from Juniperus erectopatens (Cheng and L. K. Fu) R. P. Adams and identified as (E,E,E)-1,7-dimethylcyclodeca-1,4,7-triene (pregeijerene B). Geometry of the disubstituted double bond was determined by IR and NMR spectroscopy, while that of the trisubstituted double bonds was proven by comparison of the products of selective hydrogenation of the title compound and of pregeijerene. Common biosynthesis of pregeijerene B and a germacrane sesquiterpenoid, 8alpha-acetoxyhedycaryol, is inferred from their co-occurrence in foliage of 24 Juniperus species.
authors.affiliation: University of California Forest Products Laboratory, 1301 S 46th St, Richmond, CA 94804, USA. larry.cool@ucop.edu
authors.forename: Laurence G
authors.initials: LG
authors.lastname: Cool
authors.forename: Robert P
authors.initials: RP
authors.lastname: Adams
mesh_terms: D002849:Chromatography, Gas; D006844:Hydrocarbons, Cyclic / Q000737:chemistry* / Q000302:isolation & purification; D006865:Hydrogenation; D007536:Isomerism; D018653:Juniperus / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D018515:Plant Leaves / Q000737:chemistry
chemical_list: D006844:Hydrocarbons, Cyclic; C474392:pregeijerene B