Trimethyl sulphoxonium iodide

TMSOI (Trimethyl sulphoxonium iodide) is usually used as pharmaceutical intermediates. Trimethylsulfoxonium iodide is useful for preparing ylides in strong base condition. The Treatment with strong base (such as sodium hydride) yields the ylide which adds to the carbonyl group of ketones and aldehydes to generate the Corey-Chaykovsky reagent. Also cyclopropanation can be carried out in ionic liquids with high yields preferentially to the double bond of alpha,beta-unsaturated esters to give cyclopropyl esters.