title: Regiocontrolled Synthesis of γ-Hydroxybutenolides via Singlet Oxygen-Mediated Oxidation of 2-Thiophenyl Furans.
abstract: Photooxygenation of 2-thiophenyl-substituted furans in ethanol leads to the rapid, regiocontrolled, and quantitative synthesis of γ-hydroxybutenolides. The carbonyl group in butenolide holds the position of thiophenyl moiety in reacting furans. Decomposition of the initially formed [4 + 2] endoperoxide into products through a radical chain mechanism is proposed, as the fate of thiophenyl moiety is its transformation into ethyl phenylsulfenate (PhS-OEt) and diphenyldisulfide. Under the reaction conditions, the sulfenate is fast oxidized into the corresponding sulfinate.
authors.affiliation: Department of Chemistry, University of Crete , 71003 Voutes, Iraklion, Greece.
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Kotzabasaki
authors.affiliation: Department of Chemistry, University of Crete , 71003 Voutes, Iraklion, Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Vassilikogiannakis
authors.affiliation: Department of Chemistry, University of Crete , 71003 Voutes, Iraklion, Greece.
authors.forename: Manolis
authors.initials: M
authors.lastname: Stratakis