Electrochemical oxidation of cycloalkenes and cycloalkanes into α,ω-dicarboxylic acids or into ketocarboxylic acids and cycloalkanone compounds

A process for producing unsubstituted or at least monosubstituted α,ω-dicarboxylic acids or ketocarboxylic acids and unsubstituted or at least monosubstituted cycloalkanones by electrochemical oxidation, the process comprising:

• (a-1) providing at least one unsubstituted or at least monosubstituted, monounsaturated or polyunsaturated cycloalkene;
• (a-2) providing at least one unsubstituted or at least monosubstituted, saturated cycloaliphatic hydrocarbon,
• wherein substituents of the at least monounsaturated or polyunsaturated cycloalkene and substituents of the saturated cycloaliphatic hydrocarbon are each independently selected from the group consisting of methyl, phenyl and benzyl substituents, wherein the phenyl and benzyl substituents are themselves each unsubstituted or monosubstituted or polysubstituted with 1, 2 or 3 substituents, each independently selected from the group consisting of F, Cl, Br and NO2, and
• wherein ring sizes of the cycloalkene according to (a-1) and of the cycloaliphatic hydrocarbon according to (a-2) match;
• (b) providing at least one inorganic or organic nitrate salt,
• wherein the nitrate salt of (b) is present as a nitrate of formula [cation+][NO3−], where [cation+] is selected from the group consisting of Na+, K+, ammonium ions having structure [R1R2R3R4N+] where R1, R2, R3 and R4 are each independently selected from the group consisting of C1 to C16 alkyl,
• imidazolium cations of structure (I)
• where R1′ and R2′ are each independently selected from the group consisting of C1 to C18 alkyl, and R3′ is selected from the group consisting of H and C1 to C18 alkyl, pyridinium cations of structure (II)
• where R1″ is selected from the group consisting of C1 to C18 alkyl and R2″, R3″, and R4″ are each independently selected from the group consisting of H, and straight-chain or branched C1 to C18 alkyl,
• and phosphonium ions of structure [R1aR2aR3aR4aP+] where R1a, R2a, R3a, and R4a are each independently selected from the group consisting C1 to C16 alkyl, and
• (c) electrochemically oxidizing the at least one unsubstituted or at least monosubstituted, monounsaturated or polyunsaturated cycloalkene provided in (a-1) and the at least one unsubstituted or at least monosubstituted, saturated cycloaliphatic hydrocarbon provided in (a-2) in the presence of the at least one inorganic or organic nitrate salt provided in (b) in an electrolysis cell in a reaction medium in the presence of oxygen.