ELECTROCHEMICAL REDUCTION OF OXIMES IN APROTIC MEDIA

The electrochemical reduction in N,N-dimethylformamide of (Z)- and (E) -benzaldoximes, derivatives thereof and some ketoximes has been invest igated. The bases electrogenerated during the reduction of the benzald oximes and their derivatives induce a catalytic elimination reaction p roducing benzonitrile. Two mechanisms are discussed, one in which the electrogenerated base eliminates water from the incoming substrate and one in which the base abstracts a proton from the intermediate benzal dimine radical with formation of benzonitrile radical anion; this radi cal anion then reduces the incoming substrate. The electrogenerated ba se formed during the reduction of the ketoximes deprotonates the oxime to the less reducible oxime anion. During the reduction of an acylate d oxime: the parent oxime is formed, probably by cleavage induced by t he electrogenerated base, but direct cleavage of the radical anion to the oxime might be possible.