title: Bismuth(III) triflate-catalyzed synthesis of substituted 2-alkenylfurans.
abstract: A convergent synthesis of the title compounds is reported, which relies on a successive 2-fold SN'-type substitution reaction at methoxy-substituted propargylic acetates. The furan C3-C4 bond is presumably established by silyl enol ether attack at a propargylic cation intermediate. The resulting α-methoxyallene is intramolecularly substituted, leading to cyclization by displacement of the methoxy group (O-C2 bond formation) and to simultaneous formation of the exocyclic alkene double bond. Despite the relatively mild conditions, the reactions were complete within 5 min.
authors.affiliation: Lehrstuhl für Organische Chemie I and Catalysis Research Center (CRC), Technische Universität München , Lichtenbergstr. 4, 85747 Garching, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: Nitsch
authors.forename: Thorsten
authors.initials: T
authors.lastname: Bach
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D001729:Bismuth / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D008698:Mesylates / Q000737:chemistry*
chemical_list: D000475:Alkenes; D005663:Furans; D008698:Mesylates; C445789:Bi(OTf)3; D001729:Bismuth