Stereochemistry of the [3+2] cycloaddition of acrylonitrile to the N-oxide of 5-methyl-4,5-dihydro-3H-spiro[benz-2-azepine-3,1′-cyclohexane]

The [3+2] cycloaddition of acrylonitrile to the N-oxide of 5-methyl-4,5-dihydro-3H-spiro[benz-2- azepine-3,1′-cyclohexane] under conditions of both kinetic and thermodynamic control proceeds without regioselectivity or stereoselectivity with the formation of eight isomeric 1-cyano- and 2-cyano-7-methyl-1,2,4,6,7,11b-hexahydro-5H-spiro [isoxazolidino[3,2-a]benz-2-azepine-5,1′-cyclohexanes], six of which were isolated in an individual state. Their structure and stereochemistry were established by 1H NMR.