| Abstract: | Reaction of several α,β-unsaturated ketoximes with N-bromosuccinimide (NBS) gave isoxazoles, but yields were lower and the reaction less general than a similar transformation using iodine under basic conditions. With β,β-disubstituted oximes, 4-halo-5,5-disubstituted-2-isoxazolines were obtained using NBS, iodine, or N-chlorosuccinimide. Treatment of the 4-bromoisoxazo-lines with silver acetate or silver nitrate caused either elimination with rearrangement to give isoxazoles or substitution at C-4, depending upon the nature of the substituents at C-5. |
