Tetra-tert-butylethylene
Tetra-"tert"-butylethylene is a hypothetical organic compound, a hydrocarbon with formula CH, or ((HC−)C−)C=C(−C(−CH)). As the name indicates, its molecular structure can be viewed as an ethylene molecule HC=CH with the four hydrogens replaced by "tert"-butyl −C(−CH) groups. As of 2006, this compound had not yet been synthesized, in spite of many efforts. It is of interest in chemical research as an alkene whose double bond is strained but protected by steric hindrance. Theoretical studies indicate that the molecule should be stable, with a strain energy of about .