title: 1,3-Dipolar Activity in Cycloadditions of an Aliphatic Sulfine(,)(1).
abstract: 2,2,4,4-Tetramethyl-3-thioxocyclobutanone S-oxide (4) combines with diaryl thioketones at room temperature furnishing spiro-1,2,4-oxadithiolanes 6 in equilibrium reactions. Compound 6a was oxidized to the cis-S,S-dioxide 9, the structure of which was established by X-ray analysis. These are the first unequivocal 1,3-cycloadditions of thione S-oxides (sulfines) which possess an allyl anion type MO; cycloadditions to the C=S bond of sulfines as dipolarophile and dienophile had been described before.
authors.affiliation: Institut für Organische Chemie der Universität München, Karlstrasse 23, D-80333 München, Germany.
authors.forename: Rolf
authors.initials: R
authors.lastname: Huisgen
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Mloston
authors.forename: Kurt
authors.initials: K
authors.lastname: Polborn