Reduction, Including Addition Reactions Other than Cycloaddition

Reduction, Including Addition Reactions Other than Cycloaddition 

Polarographic or electrochemical reductions have been reported for quinolizinium salts and for benzoquinolizinium salts. Controlled-potential electrolysis of the tetramethoxycarbonyl quinolizinium perchlorate (101) proceeded as shown in Eq. (44) for an aqueous phase with a mercury cathode.121 In dimethylformamide at a potential of —0.5 V the red dimer 102 was obtained. 

The polarographic reduction of benzo[a]- and benzo[6]quinolizinium salts has been examined by Frost and Saylor.122,1 23 Three derivatives of the benzo[a]quinolizinium ion were examined all showed one wave independent of pH, ascribed to the 2-electron process shown in Eq. (45). The 

Tanaka, and J. Nakaya, Denki Kayaku Koyyo Bulsuri Kayaku 42, 223 (1974) [CA 81, 135919(1974)]. 

11-dimethyl derivative had a half-wave potential less negative than those of the 7-methyl or 7,10-dimethyl derivatives, an effect ascribed to some loss of planarity because of steric hindrance. 

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B. Reduction, Including Addition Reactions Other than Cycloaddition... 

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