2-Furanacrylic acid gave 1, 4-pentadien-3-one-1, 5-dicarboxylic acid in a fairly good yield by treatment with aqueous hydrogen peroxide containing hydrochloric acid. This acid underwent the same photochemical change by direct sunlight as its methyl ester. This acid was reduced to γ-ketopimelic acid hydrazones of the acid by aluminium amalgam, and oxidised to fumaric and oxalic acids by potassium permanganate. It is assumed that the ...