title: Triumphalone, a diketone from the volatile oil of the leaves of Melaleuca triumphalis, and its spontaneous conversion into isotriumphalone.
abstract: The major component (35-65%) of the volatile oil obtained by steam distillation of the leaves of Melaleuca triumphalis has been identified as (rel)-1beta-pentyl-1alpha,6alpha-dihydroxy-3,3,5,5-tetramethylcyclohexa-2,4-dione (trivial name triumphalone). Relative stereochemistry was established by nuclear Overhauser experiments and X-ray studies on the 2-(3,5-dinitrobenzoic acid) derivative. The remainder of the oil was composed of mono- and sesquiterpene hydrocarbons and alcohols. On prolonged standing the presence of a rearrangement product of triumphalone was observed which was characterized as (rel)-1beta-pentyl-1alpha,3alpha-dihydroxy-4,4,6,6-tetramethylcyclohexa-2,5-dione (trivial name isotriumphalone), presumably arising from an acid catalyzed shift of the pentyl group from C-1 to C-2.
authors.affiliation: Department of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Brophy
authors.forename: Donald C
authors.initials: DC
authors.lastname: Craig
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Goldsack
authors.forename: Christopher J R
authors.initials: CJ
authors.lastname: Fookes
authors.forename: David N
authors.initials: DN
authors.lastname: Leach
authors.forename: Peter G
authors.initials: PG
authors.lastname: Waterman
mesh_terms: D007659:Ketones / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D031650:Melaleuca / Q000737:chemistry*; D015394:Molecular Structure; D009822:Oils, Volatile / Q000737:chemistry / Q000302:isolation & purification*; D018515:Plant Leaves / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D007659:Ketones; D009822:Oils, Volatile; C516711:triumphalone