Stereoselectivities in AgBF4-catalyzed and photoinduced phenyl- rearrangement of 2-chloropropiophenone

Article abstract of DOI:10.1016/S0040-4039(98)02284-9

(S)-2-Phenylpropionic acid was stereoselectively obtained by the AgBF₄- catalyzed phenyl-rearrangement of (S)-2-chloropropiophenone dimethyl acetal, while the photoirradiation of (S)- or (R)-2-chloropropiophenone afforded partially racemized (S)-or (R)-2-phenylpropionic acid, respectively. An intramolecular S(N)2 mechanism is suggested for the former rearrangement. The latter result is indicative of the intervention of an ion or radical intermediate in the photoinduced phenyl-rearrangement.