Magnetic Isotope and External Magnetic Field Effects upon the Photo-Fries Rearrangement of 1-Naphthyl Acetate

Article abstract of DOI:10.1021/j100261a013

The reaction mechanism of the photo-Fries rearrangement of 1-naphtyl acetate has been studied by means of steady-state photolysis and laser flash photolysis.A radical pair consisting of the 1-naphtoxyl and acetyl radicals is concluded to be a reaction intermediate.The yield of an in-cage product (2-acetyl-1-naphtol) exhibits a positive external magnetic field effect for the ester labeled by magnetically active 13C, but no effect for the normal 12C ester.The magnetic field effect observed for the abeled ester is quantitatively or semiquantitatively explained in terms of the radical-pair mechanism by considering hyperfine coupling between magnetically active nuclei (1H and 13C) and an unpaired electron in the acetyl radical.The in-cage product is formed through the singlet radical pair.