New Aspects of the Fries Rearrangement

yields identical within the error limit with those in Table 1. Phenolic esters of aliphatic carboxylic acids also undergo Fries rearrangement with TFMS. Electron donors in position 3 of the phenolic ester favor the TFMS-catalyzed rearrangement as the results in Table 1 indicate: starting from ( I d ) , ( 2 d ) was obtained in 78 % yield while ( 1 b ) remained unchanged under the reaction conditions. Surprisingly, ( I e ) did not rearrange even though the two methyl groups at C-3 and C-5 should enhance acylation of the arene nucleus. This finding can be rationalized in terms of reversibility of the Fries rearrangemen t.