Anchimerically Assisted Cleavage of Aryl Methyl Ethers by Aluminum Chloride‐Sodium Iodide in Acetonitrile

Abstract A practical method is developed for the cleavage of catechol monomethyl ethers and o ‐carbonylphenyl methyl ethers using aluminum chloride and sodium iodide in acetonitrile. Acid scavengers such as 1,3‐diisopropylcarbodiimide and CaO are used to prevent acid‐labile functional groups from side‐reactions. This method is efficient for the deprotection of various o ‐hydroxyphenyl methyl ethers such as acetovanillone, eugenol, guaiacol, vanillin, isovanillin and ortho ‐vanillin. The AlCl 3 ‐NaI system is less efficient than AlI 3 for the cleavage of other typical aryl alkyl ethers without a neighboring hydroxyl or carbonyl group, or for the removal of bulkier alkyl groups from catechol monoalkyl ethers. This procedure represents a convenient approach for the preparation of catechols.