Hydroxybenzoquinone


A hydroxybenzoquinone is any of several organic compounds that can be viewed as derivatives of a benzoquinone through replacement of one hydrogen atom by a hydroxyl group.
In general, the term may mean any benzoquinone derivative where any number n of hydrogens have been replaced by n hydroxyls, so that the formula is. In this case the number n is indicated by a multiplier prefix.
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 — as in 2,3-dihydroxy-1a,4a-dihydrobenzene-1,4-dione.
The hydroxybenzoquinones include many biologically and industrially important compounds, and are a building block of many medicinal drugs.

List of compounds

From 1,4-benzoquinone

Due to the symmetry of the 1,4-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

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