Anodic oxidation of 5-alkyl-2-furoic acids (4 and 10) in protic solvents has been studied. The major products were 1-butenolides (12, 13, 16, and 17) and γ-keto esters (11 and 15) and their acids (14 and 18). Methyl 5-n-hexyl-2, 5-dimethoxy-2, 5-dihydro-2-furoate 19 was converted into γ-keto ester 11 and its acid 14 by hydrolysis with alkali and into 1-butenolide 12 by electrolysis of the alkaline solution. A possible mechanism of the anodic oxidation of ...