Barrelene is a bicyclic organic compound with chemical formula C₈H₈ and systematic name bicyclo[2.2.2]octa-2,5,7-triene.
First synthesized and described by Howard Zimmerman in 1960, the name derives from the resemblance to a barrel, with the staves being three ethylene units attached to two methine groups.
It is the formal Diels–Alder adduct of benzene and acetylene.
Due to its unusual molecular geometry, the compound is of considerable interest to theoretical chemists.

Iptycenes, with the alkene groups part of an arenes,  are related compounds.
It is also a starting material for many other organic compounds, such as semibullvalene.

The original Zimmerman, synthesis modified in 1969, starts from coumalic acid:
Many alternative routes have been devised since then, one of them starting from oxepin:  
An alternate route that allows synthesis of the parent barrelene system and a variety of substituted barrelenes has also been reported
Barrelene is a bicyclic organic compound with chemical formula C₈H₈ and systematic name bicyclo[2.2.2]octa-2,5,7-triene. First synthesized and described by Howard Zimmerman in 1960, the name derives from the resemblance to a barrel, with the staves being three ethylene units attached to two methine groups. It is the formal Diels–Alder adduct of benzene and acetylene. Due to its unusual molecular geometry, the compound is of considerable interest to theoretical chemists.
Iptycenes, with the alkene groups part of an arenes,  are related compounds. It is also a starting material for many other organic compounds, such as semibullvalene.
The original Zimmerman, synthesis modified in 1969, starts from coumalic acid:
Many alternative routes have been devised since then, one of them starting from oxepin:  
An alternate route that allows synthesis of the parent barrelene system and a variety of substituted barrelenes has also been reported
Barrelene