Photo-Fries thioesters

Photolysis of 2-naphthyl thioesters in the presence of a hydrogen donor such as 1,4-cyclohexadiene yields aldehydes (80-100%) no photo-Fries reaction products have been reported [60],... 

With regard to the mechanism of the solid state photoreactions, there are two possible pathways from the starting amides 53 to phthalides 54 either phenyl migration, which is the same as in the mechanism of thioester derivatives 51, or the mechanism initiated by homolytic cleavage of the C( = 0)-N bond to generate a radical pair intermediate. The radical mechanism has been confirmed in the photo-Fries rearrangement of aromatic amides. To answer the question of the... 

More than half a century ago, Anderson and Reese reported the first example of a photo-Fries rearrangement (PFR), where 2-hydroxyphenylacetate was converted into 2,3- and 3,4-dihydroxy acetophenone upon UV irradiation [1]. Since then, hundreds of articles have appeared on this reaction, which has been extended from the initial aryl esters to amides, carbonates, carbamates, thioesters, sulfonates, etc. [2-4]. 

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See also in sourсe #XX -- [ ]

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