Selective methoxy ether cleavage of 2,6-dimethoxyphenol followed by a selective acylation

Tetrahedron Lett. 2012 Jan 4;53(1):11-14. doi: 10.1016/j.tetlet.2011.10.140.

Abstract

A Friedel-Crafts reaction of 2,6-dimethoxyphenol in the presence of aluminum chloride and propanoyl or butanoyl chlorid, respectively, lead, at elevated temperatures, to a selective cleavage of one of the methoxy groups followed by a selective acylation of the meta position with respect to the phenolic hydroxyl group. Under the same reaction conditions 2-methoxyphenol doesn't get demethylated; a mechanism to account for these findings is proposed. This reaction gives access to a variety of ortho-acylated catechols. Substituted catechols are widely used in supramolecular chemistry and are precursors of pesticides, flavors and fragrances. Additionally, catechol moieties are found in various natural products.