1,3-Cyclohexadiene

1,3-Cyclohexadiene is an organic compound with the formula (CH₂)₂(CH)₄. It is a colorless, flammable liquid. Its refractive index is 1.475 (20 °C, D). A naturally occurring derivative of 1,3-cyclohexadiene is terpinene, a component of pine oil.

Synthesis

Cyclohexadiene is prepared by the dehydrobromination of 1,2-dibromocyclohexane:

1,3-Cyclohexadiene can also be prepared by the electrocyclic reaction from 1,3,5-hexatriene either photochemically or at temperatures above 110 °C.

Reactions

1,3-Cyclohexadiene can be used as a hydrogen donor in transfer hydrogenation, since its conversion to benzene + hydrogen is exothermic by about 25 kJ/mol (gas phase).

Compared with its isomer, 1,4-cyclohexadiene, 1,3-cyclohexadiene is about 8.5 kJ/mol more stable.

See also

References