Asymmetry by Electrophilic Rearrangement of Symmetric 2-Pyridone Photodimers

Halogenation of achiral <i>trans</i>-2-pyridone photodimers results in 1,3-migration of an amide nitrogen and formation of a chiral structure with six stereogenic centers and well-differentiated functionality. The reactivity of this product toward nucleophiles, including the allylic halide, is dominated by participation by the amide nitrogen.