Methylthiomethyl ether cleavage

Cleavage of methyl ethers. Alkyl methyl ethers are converted into acetates in high yield on contact with these two reagents. Both alkyl and aryl methylthiomethyl ethers are cleaved in 60-70% yield by this system. Tertiary alcohols can be acetylated by this reaction (two examples, 90% yield)... 

Saponification. Corey etal. employed 2,2 -dihydroxydiethyl sulfide to suppress cleavage of the methylthiomethyl ether group during the hydrolysis of the lactone 1 with Li0H-H202. Treatment of the saponification product with KOH (to effect benzoic ester cleavage) and then diazomethane gives 2, a key intermediate in the synthesis of erythronolide A (3). 

Some of the methods used to cleave methylthiomethyl (MTM) ethers should also be applicable to the cleavage of tetrahydrothiofuranyl ethers. 

Full details have now appeared of the general method for formation of methylthiomethyl (MTM) ethers from alcohols by treatment with DMSO in acetic anhydride containing acetic acid. These authors also report their mild cleavage method of methyl iodide in moist acetone the use of volatile reagents is advantageous as it allows easier product isolation than the previous Ag and Hg procedures. 

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