title: An efficient procedure for the preparation of (E)-alpha-alkylidenecycloalkanones mediated by a CeCl(3) x 7H(2)O-NaI system. Novel methodology for the synthesis of (S)-(-)-pulegone.
abstract: 2-Alkylidenecycloalkanones are powerful synthons used as the key intermediates in many important syntheses. Because of their potential, a general method of preparation from readily available starting materials, under very mild conditions, was considered to be worthwhile. Cerium(III) chloride heptahydrate in combination with sodium iodide in refluxing acetonitrile promotes a regio- and stereoselective beta-elimination reaction to (E)-2-alkylidenecycloalkanones in 2-(1-hydroxyalkyl)cycloalkanones. The synthetic value of the present procedure is demonstrated by the synthesis of monoterpene (S)-(-)-pulegone (8) in its optically active form.
authors.affiliation: Department of Chemical Sciences, University of Camerino, via S. Agostino 1, I-62032 Camerino (MC), Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bartoli
authors.forename: Marcella
authors.initials: M
authors.lastname: Bosco
authors.forename: Renato
authors.initials: R
authors.lastname: Dalpozzo
authors.forename: Arianna
authors.initials: A
authors.lastname: Giuliani
authors.forename: Enrico
authors.initials: E
authors.lastname: Marcantoni
authors.forename: Tiziana
authors.initials: T
authors.lastname: Mecozzi
authors.forename: Letizia
authors.initials: L
authors.lastname: Sambri
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Torregiani
mesh_terms: D000473:Alkanes / Q000138:chemical synthesis*; D002384:Catalysis; D002625:Chemistry, Organic / Q000379:methods*; D000081005:Cyclohexane Monoterpenes; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D039821:Monoterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000473:Alkanes; D000081005:Cyclohexane Monoterpenes; D039821:Monoterpenes; C039648:pulegone