Ethers dealkylations, iodotrimethylsilane

Alkyl esters are efficiently dealkylated to trimethylsilyl esters with high concentrations of iodotrimethylsilane either in chloroform or sulfolane solutions at 25-80° or without solvent at 100-110°.Hydrolysis of the trimethylsilyl esters serves to release the carboxylic acid. Amines may be recovered from O-methyl, O-ethyl, and O-benzyl carbamates after reaction with iodotrimethylsilane in chloroform or sulfolane at 50—60° and subsequent methanolysis. The conversion of dimethyl, diethyl, and ethylene acetals and ketals to the parent aldehydes and ketones under aprotic conditions has been accomplished with this reagent. The reactions of alcohols (or the corresponding trimethylsilyl ethers) and aldehydes with iodotrimethylsilane give alkyl iodides and a-iodosilyl ethers,respectively. lodomethyl methyl ether is obtained from cleavage of dimethoxymethane with iodotrimethylsilane. 

Cleavage of methyl and benzyl ethers.2 These ethers are cleaved by the combination of this silane and zinc iodide. The rate of dealkylation is enhanced by the presence of ( -C4H9)4NI. Trimethyl(methylthio)silane serves the same purpose. CH2C12 and C1CH2CH2C1 are satisfactory solvents. The cleavage probably does not involve in situ formation of iodotrimethylsilane. 

---