title: Dithiolopyranthione Synthesis, Spectroscopy and an Unusual Reactivity with DDQ.
abstract: The bicyclic pyran thiolone tetrahydro-3αH-[1,3]dithiolo[4,5-β]pyran-2-thione (3a) engages in a highly unusual fragmentation in the presence of DDQ. The pyran thiolone,3a, was synthesized by chlorination of 3,4-dihydro-2H-pyran (1), followed by condensing with CS2and NaSH. Reaction of3awith DDQ generates the isomerized pyran thiolone tetrahydro-3αH-[1,3]dithiolo[4,5-β]pyran-2-thione (3b) and 4-benzyl-5-(3-hydroxypropyl)-1,3-dithiole-2-thione (4) via a deep-seated rearrangement. The identity of3bwas confirmed by single crystal X-ray analysis: P21/c, a=5.807(9) Å, b = 12.99(2) Å, c = 11.445(15), β=113.23(6)°. Mechanistic experiments and computational insight is used to explain the likely sequence of events in the highly unusual formation of4. Collectively, these results establish fundamental reactivity patterns for further research in this area.
authors.affiliation: Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282.
authors.forename: Igor V
authors.initials: IV
authors.lastname: Pimkov
authors.affiliation: Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282.
authors.forename: Archana
authors.initials: A
authors.lastname: Nigam
authors.affiliation: Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282.
authors.forename: Kiran
authors.initials: K
authors.lastname: Venna
authors.affiliation: Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282.
authors.forename: Fraser F
authors.initials: FF
authors.lastname: Fleming
authors.affiliation: Department of Chemistry, The University of Minnesota-Duluth, Duluth, MN 55812.
authors.forename: Pavlo V
authors.initials: PV
authors.lastname: Solntsev
authors.affiliation: Department of Chemistry, The University of Minnesota-Duluth, Duluth, MN 55812.
authors.forename: Victor N
authors.initials: VN
authors.lastname: Nemykin
authors.affiliation: Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282.
authors.forename: Partha
authors.initials: P
authors.lastname: Basu