Thiirenium salts

The thiirenium salt 30 reverted to starting materials 29 and cyclooctyne by addition of K2CO3 as a base. This probably results from nucleophilic attack on the thiirenium sulfur atom by the side chain hydroxyl group <2002JA8316>. 

Thiiranium ions were proposed as intermediates in acid-catalyzed sulfur-atom transfer from sultene 29 to cyclic olefins under thermal conditions (Scheme 45). A high degree of diastereospecificity was observed during the sulfur atom transfer reaction to /ra r-cyclooctene. S-Dealkylation is facilitated by the formation of a stablilized carbocation, which may further cyclize or rearrange <1998JA4861>. Similar sulfur-atom transfer to cyclooctyne afforded a relatively stable thiirenium salt that did not undergo S-dealkylation (Section 1.06.5.2) <2002JA8316>. 

Thiirenium salts. The thiirenium salt (2) is formed quantitatively (NMR spectroscopy) by reaction of (1) with 2-butyne at -80° in liquid SO2. The salt is stable for hours at -70 to -50°. It is also formed as a transient species by the... 

THIIRANES 3-Methylbenzothiazole-2-thione. 2-Thiomethyl-4,4-dimethyl-2-oxazoline. THIIRENIUM SALTS Methyl(bismethylthio)sulfonium hexachloroantimonate. THIOACYL CHLORIDES Hydrogen chloride. 

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