Trimethylsulfoxonium iodide

Chemical properties

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The Uses of Trimethylsulfoxonium iodide

Trimethylsulfoxonium Iodide is used to synthesize methylene-transfer reagents that are used in the preparation of epoxides.

The Uses of Trimethylsulfoxonium iodide

Treatment with strong base yields the ylide which adds to the carbonyl group of ketones1 and aldehydes2,3 to give epoxides. Also adds preferentially to the double bond of α,β-unsaturated esters to give cyclopropyl esters.4,5

The Uses of Trimethylsulfoxonium iodide

Trimethylsulfoxonium iodide is a sulfoxonium salt. It is used to generate dimethyloxosulfonium methylide by reaction with sodium hydride. The latter compound is used as a methylene-transfer reagent, and is used to prepare epoxides.

Synthesis

Trimethylsulfoxonium iodide is commonly prepared by a reaction of Dimethyl Sulfoxide with ≈2.5 equiv of Iodomethane. After refluxing for 24 h at 80?°C, the reaction mixture is cooled, and the crude solid product is filtered and washed with acetone to give the trimethylsulfoxonium iodide. Iodomethane has to be handled in a fume hood because of its high volatility and toxicity. Excess MeI is used to ensure the completion of the reaction.

Storage

The iodide and chloride salts are hygroscopic and must be stored in a cool, dry place. They are incompatible with strong oxidizing agents and strong bases. The iodide salt is sensitive to light and needs to be protected from light as much as possible.