title: Synthesis of thienothiopyranthiones by a new molecular rearrangement.
abstract: On heating with alkynes, the readily prepared 1,3-dithioles 3 undergo a new cycloaddition reaction and an unprecedented molecular rearrangement with loss of chlorine to give the first 7H-thieno[2,3-c]thiopyran-7-thiones 4 and 4H-thieno[3,2-c]thiopyran-4-thiones 5 whose structures were confirmed by X-ray diffraction. Unexpectedly, the different alkynes used to form 3 and to convert it into 4 and 5 were incorporated regiospecifically into the thiophene and thiopyran rings, respectively. [reaction: see text]
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect, 47, 119991 Moscow, Russia.
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Ogurtsov
authors.forename: Oleg A
authors.initials: OA
authors.lastname: Rakitin
authors.forename: Charles W
authors.initials: CW
authors.lastname: Rees
authors.forename: Alexey A
authors.initials: AA
authors.lastname: Smolentsev
authors.forename: Pavel A
authors.initials: PA
authors.lastname: Belyakov
authors.forename: Denis G
authors.initials: DG
authors.lastname: Golovanov
authors.forename: Konstantin A
authors.initials: KA
authors.lastname: Lyssenko