Synthesis and interconversion of 6‐aroyl‐4‐oxohexanoie acids and 5‐aryl‐2‐furanpropionic acids. Antiinflammatory agents

A series of 6‐aroyl‐4‐oxohexanoic acids ( 2 ) was prepared for intermediate use by acid‐catalyzed solvolysis of substituted 3‐(2‐furyl)acrylophenones ( 1 ). This reaction occasionally gave 5‐aryl‐2‐furanpropionic acids ( 3 ) instead of, or in addition to, the desired diketones ( 2 ). Equilibrium between 2 and 3 was observed in the case where Ar is m ‐nitrophenyl. A rationalization for the formation of 3 is offered, and published reports with which our results differ are discussed. Diketones ( 2 ) were cyclized to furans ( 3 ) and antiinflammatory screening data are reported for the latter.