Thiono-l,3-dioxol-4-ene

Cyclization with Dienes. The reaction of 2-thiono-l,3-dioxol-4-ene with anthracene at elevated temperatures leads to the production of the bicyclic adduct (1) (eq 1). No other dienes have been reported to cyclize with this reagent. Diels-Alder adducts could be treated with phosphines to effect a Corey-Winter aUcenation, which would render the reagent an acetylene equivalent. 

Synthesis of Ketene. Photolysis (270 nm) of 2-thiono-l,3-dioxol-4-ene results in the quantitative formation of ketene via Wolff rearrangement of the corresponding a-ketocarbenes (eq 2). Substituted dioxolenes can also be used in this fashion to generate substituted ketenes (eq 3). This serves as a convenient alternative to the use of a-diazo ketones in the generation of ketenes. 

Preparation of Dication Dichalcogenides. Treatment of 2-thiono- l,3-dioxol-4-ene with trifluoromethanesulfonic anhydride... 

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