Formation of O-Allyl Oximes by Reaction of Allylzinc Reagents with α-Chloronitroso Compounds

ABSTRACT The reaction of α-chloronitrosocyclohexane with allyl­zinc reagents in THF selectively provides O-allylcyclohexanone oximes in very good yields in an ene type reaction followed by zinc halide elimination. N-Allyl hydroxylamines are formed as minor products via N-allyl nitrones when a nonpolar solvent, e.g. toluene, is employed. In both cases complete allylic transposition with respect to the allylic organozinc reagent is observed. Compared to non-metalated allyl compounds, which give N-allyl nitrones upon reaction with α-chloronitroso compounds, the use of zinc as hydrogen equivalent in an ene type reaction displays a drastic change of reactivity.