Biphenyl, anodic processes

Continuing interest in the development of preparatively useful anodic C-C bond-forming reactions has led to detailed investigations of the intramolecular trapping of phenoxonium ions by alkenyl side chains in anodic oxidation of phenolic biphenyl derivatives [56-58]. In this process, solvent trapping by methanol occurs after the phenoxonium ion has been intercepted by the side-chain 7r-bond. As shown in Table 3, a variety of substituted spirodienones (LVII) may be prepared from the corresponding phenolic biphenyls (LVI) under constant-current electrolysis conditions. 

The major application of electrochemical ozone cells is in the oxidation of water-based species (in order to provide sterilization) and the oxidation of industrial process liquors containing cyanides or organicSte.g. phenols, dyes and pesticides, In such applications it is environmentally more desirable than CI2 or OCl" treatment (Chapter 7) as the latter chemicals may leave a range of undesirable species. Ozone treatments may be advantageously coupled with ultraviolet treatments in order to remove certain persistent chemicals (such as certain pesticides or polychlorinated biphenyls). In the case of sterilization of potable water the cells are likely to remain small modular designs (Fig. 5,15(b)). While the O3 required is very dependent on inlet-water quality, a cell of 100 cm anode area may service up to KKK) m day of water at the 1 mg dm O3 dose level... 

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