Is benzene a common name for cyclohexene?

[devenpatel2O]

Why is benzene "benzene?" What makes cyclohexene different from benzene? Both seem to have 6 carbons in a ring structure and the same "kekule" looking structure? What is going on?

Thanks,

Deven

[Neil DSilva 1L]

They have difference numbers of hydrogen atoms attached to the carbons and a different number of double bonds and that's probably the biggest difference, benzene is a completely different class. The number of carbons is just one part the nomenclature, you also have to consider what else makes up the molecule.

The molecular formula for cyclohexene is while the molecular formula for benzene is . In addition, cyclohexene only has one double bond, so it doesn't have the same "kekule" structure as benzene.

[Chem_Mod]

Benzene is the name for the molecule which we would otherwise call "Cyclohexatriene" where the "tri-ene" indicates that there are THREE double bonds on the ring of six carbons.

However, since benzene is so important and has properties distinct from alkenes (it is stable and won't easily undergo electrophilic addition to a double bond!), we do not call it cyclohexatriene.