A hydroxybenzoquinone (formula: C
6
H
4
O
3
) is any of several organic compounds that can be viewed as derivatives of a benzoquinone through replacement of one hydrogen atom (H) by a hydroxyl group (-OH).

In general, the term may mean any benzoquinone derivative where any number n of hydrogens have been replaced by n hydroxyls, so that the formula is C
6
H
4
O
2+n
. In this case the number n (which is between 1 and 4) is indicated by a multiplier prefix (mono-, di-, tri-, tetra-, penta-, or hexa-).

The unqualified term "hydroxybenzoquinone" usually means a derivative of 1,4-benzoquinone. Other hydroxy- compounds can be derived from the other isomer, namely 1,2-benzoquinone or ortho-benzoquinone. The IUPAC nomenclature uses dihydrobenzenedione instead of "benzoquinone", with the necessary prefixes to indicate the positions of the carbonyl oxygens (=O) — as in 2,3-dihydroxy-1a,4a-dihydrobenzene-1,4-dione (= 2,3-dihydroxy-1,4-benzoquinone).

The hydroxybenzoquinones (in the particular or the general sense) include many biologically and industrially important compounds, and are a building block of many medicinal drugs.[1][2]

List of compounds

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From 1,4-benzoquinone

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Due to the symmetry of the 1,4-benzoquinone (para-benzoquinone) core, there is only one distinct isomer with 1, 3, or 4 substituted hydroxyls, and three isomers with 2 hydroxyls:

From 1,2-benzoquinone

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From the less symmetrical 1,2-benzoquinone (ortho-benzoquinone) there are 9 possible isomers:

See also

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References

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  1. ^ Thomson R.H. Naturally Occurring Quinones. Academic Press, London (1971). Quoted by Khalafy and Bruce.
  2. ^ Thomson R.H. Naturally Occurring Quinones III. Chapman and Hall, London (1987). Quoted by Khalafy and Bruce.