Annelated furans. XII. Fries rearrangement of isocreosol esters

Abstract

The Fries reaction of 2-methoxy-5-methylphenyl butyrate (5) in the presence of titanium tetrachloride gave only the para rearrangement product, 4-hydroxy-5-methoxy-2-methylphenyl propyl ketone (6). Irradiation of the ester (5) gave the ortho rearrangement product, 2- hydroxy-3-methoxy-6-methylphenyl propyl ketone (7), in addition to (6), isocreosol, and 2-hydroxy-4-methylphenyl propyl ketone (8). The photorearrangement of 3-nitropropionate esters of isocreosol and related phenols did not proceed satisfactorily as the 3-nitropropionyl group appeared unstable under these conditions. However, the photo- Fries rearrangement of the corresponding 3-chloropropionate esters proceeded normally with the formation of o- and p-hydroxyphenyl 2- chloroethyl ketones, and in addition the substituted o-hydroxyphenyl vinyl ketones, generated by elimination of hydrogen chloride from the corresponding ortho rearrangement product.