1,4-Benzoquinone

1,4-Benzoquinone is the chemical compound with the formula C6H4O2. This nonaromatic six-membered ring compound is the oxidized derivative of 1,4-hydroquinone. The molecule is multifunctional: it exhibits properties of a ketone, forming an oxime; an oxidant, forming the dihydroxy derivative; and an alkene, undergoing addition reactions.

Applications in organic synthesis
It is used as a hydrogen acceptor and oxidant in organic synthesis. 1,4-Benzoquinone serves as a dehydrogenation reagent. It is also uses as a dienophile in Diels Alder reactions.

Related 1,4-benzoquinones
A variety of derivatives and analogues are known. Illustrative examples:
 * 1,4-Naphthoquinone, derived by oxidation of naphthalene with chromium trioxide.
 * 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, a stronger oxidant and dehydrogenation agent than 1,4-benzoquinone.
 * Ubiquinone-1, a naturally occurring 1,4-benzoquinone.
 * Chloro-p-benzoquinone, (CAS no. [695-99-8])
 * Chloranil, 1,4-C6Cl4O2, a stronger oxidant and dehydrogenation agent than 1,4-benzoquinone.