Cyclohexenone is an organic compound which is a versatile intermediate used in the synthesis of a variety of chemical products such as pharmaceuticals and fragrances. It is colorless liquid, but commercial samples are often yellow.
Industrially, cyclohexenone is prepared from phenol by Birch reduction.
Cyclohexenone is a ketone, or more precisely an enone. Common reactions include nucleophilic conjugate addition with organocopper reagents,  Michael reactions and Robinson annulations.