A photorearrangement of aryl or acyl esters to give the [1,3]-rearranged product (as well as the [1,5]-rearranged product):
P04614.png
Source:
PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2261 (https://doi.org/10.1351/pac199668122223)