Iminyl radicals in gas-phase synthesis. III. Synthesis of a terminally unsaturated nitrile

Abstract

The previously reported generation of α- and ω-cyanoalkyl radicals has been substantially improved by the use of the oxime esters of cyclopentanone and cyclohexanone instead of the azines. Fragmentationof the α-cyanoalkyl radicals to acrylonitrile is still observed, but the efficiency of alkylation of the residue is considerably enhanced. A synthetic device is described for intercepting the first-formedω-cyanoalkyl radicals with the formation of terminally unsaturated nitriles. This involves pyrolysis of the 5,6-dihydro-4H-l,2-oxazin-6-ones. The preparation and pyrolysis of 4,4a,5,6-tetrahydro-3H-naphth[l,2-c][1,2]oxazin-3-one to 2-(but-3-eny1)benzonitrile is described.