Fun with Furans

AbstractThe aromatic furan ring is found in a wide range of aroma chemicals, especially those produced by the Maillard reaction. They include both low‐odor materials such as furfural and high‐impact materials such as 2‐methylfuran‐3‐thiol. Among the most important are the hydroxyfuranones, especially 4‐hydroxy‐2,5‐dimethylfuran‐3(2H)‐one (HDMF, 7), which is a material of unusual reactivity. This contrasts with the inert character of its isomer sotolone. Furans are also found as trace components where they can either contribute a desirable character or an off‐note depending on context.