Bicyclopropenyl (bicycloprop-2-enyl, C6H6) is an organic compound and one of several valence isomers of benzene.

[1][2] The 3,3 isomer was formed in two steps by reaction of 1,4-bis(trimethylsilyl)buta-1,3-diene with methyllithium and dichloromethane, introducing two cyclopropane rings into the molecule.

In this latter reaction fluoride couples to the trimethylsilyl group, in the process forming the double bond and forcing the chlorine atom to leave as chloride.

In presence of silver ions bicycloprop-2-enyl rearranges to Dewar benzene.

Derivatives can be much more stable, for example perfluorohexamethylbicyclopropenyl that must be heated to 360 °C to be as unstable.