title: 2-substituted benzofuran fragment ion formation in the electron ionization mass spectra of 6-alkyl- and 6-aryldibenzo(d,f)(1,3)dioxepine derivatives. 1. Spirocyclization of the molecular ions in the gas phase.
abstract: The formation of 2-substituted benzo[b]furan ions in the electron ionization (EI) mass spectra of a series of 6-alkyl- and 6-aryldibenzo(d,f)(1,3)dioxepines has been studied by means of exact mass measurements and multiple-stage mass spectrometry conditions using an ion trap mass spectrometer. The proposed mechanism of formation of benzo[b]furan ions requires the formation of a spirocyclic cyclohexadienone system, which undergoes elimination of a cyclopentadienone molecule. A parallel with the chemical conversion of arylmethyl-substituted dibenzo(d,f)(1,3)dioxepines into an analogous spirocyclic system was also underlined.
authors: Dipartimento Farmaco Chimico Tecnologico, Università di Cagliari, Via Ospedale 72, 09124 Cagliari, Italy.
authors: Michela
authors: M
authors: Begala
authors: Graziella
authors: G
authors: Tocco
authors: Gabrielle
authors: G
authors: Meli
authors: Gianni
authors: G
authors: Podda
authors: Silvana A M
authors: SA
authors: Urru
mesh_terms: D001572:Benzofurans / Q000737:chemistry*; D003510:Cyclohexanes / Q000737:chemistry*; D053138:Cyclohexenes; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D007477:Ions / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013141:Spiro Compounds / Q000737:chemistry*
chemical_list: D001572:Benzofurans; D003510:Cyclohexanes; D053138:Cyclohexenes; D007477:Ions; D013141:Spiro Compounds; C507608:cyclohexadienone