3-Acetyl-4-(2-furyl)-3-buten-2-one (I) and ethyl α-propionyl-2-furanacrylate (V) were obtained by the condensations of furfural with acetylacetone and ethyl propionylacetate by piperidine, respectively. 3-Acetyl-4-(2-furyl)-3-buten-2-one (I) was oxidised by sodium hypochlorite to furfurylidenemalonic acid (II), and, on refluxing with alcohoric hydrochloric acid and subsequent hydrolysis, gave β-(4-acetyl-5-methyl-2-furyl)-propionic acid (IV). ...