1,2,3-Cyclohexatriene

1,2,3-Cyclohexatriene is an unstable chemical compound with the molecular formula. It is an unusual isomer of benzene in which the three double bonds are cumulated.
This highly strained compound was first prepared in 1990, by reacting a cyclohexadiene derivative with cesium fluoride. The product was too reactive to be isolated on its own, so its existence was confirmed by trapping via a cycloaddition reaction.
1,2,3-Cyclohexatriene and its derivatives undergo a variety of reactions including cycloadditions, nucleophilic additions, and σ-bond insertions, and therefore they can be versatile reagents for organic synthesis.