2.5- Dimethylfuran cyanomethoxylation

Deprotonation of 1 to give the neutral radical 2 under the conditions of anodic cyanomethoxylation has been proposed to account for the occurrence of minor products similar deprotonation has been suggested in a reaction where 2,5-dimethylfuran acts as a highly efficient scavenger for benzoyloxy radicals yielding 2-benzoyloxymethyl-5-methylfuran. The ESR spectra of 2 and its 2-methyl analog have been recorded for the radicals generated... 

The stereochemistry of the anodic cyanomethoxylation of 2,5-dimethylfuran [172] depends, at a platinum electrode, on the concentration of substrate and of additives the cis-trans ratio changes from 2.89 1 to 1.46 1 on increasing the concentration of substrate from 0.01 to 0.2 M. At a carbon anode a ratio close to the equilibrium mixture 1.42 1 is obtained. 

Anodic acetoxylation of furan can be done in acetic acid containing acetate [173, 174] and benzoyloxylation in DMF containing benzoic acid and lithium chloride [175]. A mixture of cis- and ra 5-benzoyloxylated product is formed. Cyanomethoxylation of 2,5-dimethylfuran gives a mixture of cis- and rmn5-2-cyano-5-methoxy-2,5-dimethyldihydro-furan [176-178]. 

Dimethylfuran was also anodically cyanomethoxylated in the presence of cyanide ion to give 2,5-dimethyl-2-methoxy-5-cyano-2,5-dihydrofuran in a cis—trans ratio of 1.46-2.89, which varied with the type of aromatic additive in the anolyte [310]. 

The jt-excessive character of furan facilitates single-electron oxidation however, the cation-radicals produced from simple furans are not, in general, persistent. The mediation of 2,5-dimethylfuran cation-radical (1) has been proposed in anodic oxidations yielding methoxylated, cyanomethoxylated, and acyloxylated products. Although not specifically implicated, cation-radicals may be involved in very similar oxidative reactions. ... 

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