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The electrochemical oxidation of glucose to gluconic acid and reduction of glucose to sorbitol have been paired in an undivided packed‐bed electrode flow reactor. A Raney Ni powder electrocatalyst significantly improved the current efficiency for sorbitol production, as compared to a high hydrogen overpotential normalZnfalse(normalHgfalse) cathode. The optimum operating conditions for the paired syntheses are activity W‐2 Raney Ni powder cathode, graphite chip anode, a 1.6M glucose and 0.4M CaBr2 initial solution composition, pH 5–7, 60°C solution temperature, an applied current of 250–500 mA per 10g of nickel powder cathode and a solution volumetric flow rate of 100 ml‐min−1. Under these conditions, the sorbitol current efficiencies are 80–100%, the gluconic acid efficiencies are 100%, and the product yields are very high.

Controlled potential electrolysis at a mercury cathode was used to effect two-electron reductive cleavages of carbon tetrachloride, ethyl trichloroacetate, ethyl bromoacetate, allyl chloride and bromide, benzyl chloride and bromide, ethyl 4-bromobutyrate, 4-bromobutyronitrile, and chloroacetonitrile in the presence of acrylonitrile, ethyl acrylate, diethyl fumarate, and diethyl maléate. The electrochemically generated anion nucleophilically attacked the acceptor to yield adduct anions. The latter evolved into final products by several routes: (a) by protonation, e.g., 4-trichlorobutyronitrile from CCh and acrylonitrile, (b) by cyclization-displacement of halide, e.g., diethyl l-c,hloro-l,2-cyclopropanedicarboxylate from ethyl trichloroacetate and ethyl acrylate, (c) by displacement on halogen of a polyhalo starting material, e.g., diethyl 2,2,4-trichloroglutarate also from ethyl trichloroacetate and ethyl acrylate. The factors that must be considered in the design of these electrochemical syntheses are discussed. Reduction of benzyl chloride in the presence of carbon dioxide led directly to benzyl phenylacetate. Similarly, allyl chloride produced allyl crotonate. Reductive dehalogenative coupling of allyl halides and of ethyl bromoacetate alone are also reported.

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ANALYSIS OF GOLDbecomes contaminated with anionic impurities, derived mainly from the side reactions of the KCN with water and air. Moreover, a comparison of the results of this work and those of a previous work (1) would indicate that electrolysis has an effect on the relative concentrations of the H.COO-and CO3 = ions present within a KCN/KAu(CN)2 electroplating solution.The ratio of CO3 = ion to H.COO-ion in Table VIII is approximately 0.65. Yet, in an aqueous KCN solution maintained at 70~ and exposed to air (1), in which no electrolysis is being conducted, the ratio is closer to 0.2. The higher CO3=/H.COO -ratio observed for the used electroplating solution probably results from the electrolytic oxidation of the H.COOion at the anode to CO2 (8, 9), which is retained in the alkaline KCN solution. ConclusionDibasic ammonium citrate/KAu(CN)2 and KCN/ KAu(CN)2 electroplating solutions are both susceptible to metallic impurity contamination. These impurities do not plate out of the KCN/KAu (CN)2 solution with the gold as readily as they do from the dibasic ammonium citrate/KAu (CN) 2 solution. However, the H.COO-and CO3 = ionic impurities build up to a high concentration in the KCN/KAu(CN)2 electroplating solution, but are barely present in the dibasic ammonium citrate/KAu(CN)2 electroplating solution. FOILS FOR IMPURITIES 743There is evidence that some of the H.COO-ion is oxidized at the anode to CO2, which is retained in the alkaline electroplating solution.

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Short-lived (f 1/2 < 10-3 sec) anion radicals of activated olefins (CH2=CHX with X = CO2CH3, CN, and acetyl) generated at a mercury cathode under anhydrous conditions react rapidly with carbon dioxide. Further reduction of the radical carboxylate intermediate and subsequent carboxylation results in the formation of substituted succinic acid derivatives. An alternate pathway involves electroreduction of carbon dioxide and subsequent reactions