Photochemistry of substituted phenyl phenylacetates within cyclodextrin cavities

The photochemical reactions of several substituted phenyl phenylacetates incorporated in the cavities of alpha- and beta -cyclodextrins and in organic solvents were investigated. Photolysis of these esters in organic solutions results in both photo-Fries rearrangement and photodecarbonylation products. However, the esters included in cyclodextrin cavities almost exclusively undergo photo-Fries reactions. Furthermore, in the photo-Fries reactions of the inclusion complex the ratios of ortho to para rearrangement products are evidently increased compared with those in organic solutions. Those are good examples for using cyclodextrins to control the selectivity in photochemical reactions.