Reactions of 1,1,1-trihalo-3-nitrobut-2-enes with enamines derived from cycloalkanones. Rearrangement of trifluoromethylated 1,2-oxazine N-oxide into 1-pyrroline N-oxides and stereochemistry of the products

1,2-Oxazine N-oxides derived from (E)-1,1,1-trifluoro-3-nitrobut-2-ene and cyclohexanone enamines underwent spontaneous rearrangement with ring contraction to give 1-pyrroline N-oxides. Reactions of (E)-1,1,1-trifluoro(trichloro)-3- nitrobut-2-enes with N-cyclopent-enylmorpholine resulted in a series of novel CX3-containing nitroalkyl enamines and g-nitro ketones; the stereochemistry of the synthesized compounds were studied by NMR spectroscopy and X-ray diffraction. © 2012 Springer Science+Business Media New York