A hydroxynaphthoquinone (formula: C
10H
6O
3) is any of several organic compounds that can be viewed as derivatives of a naphthoquinone through replacement of one hydrogen atom (H) by an hydroxyl group (-OH).
Contents
- From 14 naphthoquinone
- From 12 naphthoquinone
- From 23 naphthoquinone
- From 26 naphthoquinone
- Polyhydroxynaphthoquinones
- References
In general, the term may mean any naphthoquinone derivative where any number n of hydrogens have been replaced by n hydroxyls, so that the formula is C
10H
6O
2+n. In this case the number n (which is between 1 and 6) is indicated by a multiplier prefix (mono-, di-, tri-, tetra-, penta-, or hexa-).
The unqualified term "hydroxynaphthoquinone" usually means a derivative of 1,4-naphthoquinone. Other hydroxy- compounds can be derived from other isomers of the latter, such as 1,2-naphthoquinone and 2,6-naphthoquinone. The IUPAC nomenclature uses dihydronaphthalenedione instead of "naphthoquinone", with the necessary prefixes to indicate the positions of the carbonyl oxygens (=O) — as in 5,8-dihydroxy-1a,8a-dihydronaphthalene-1,4-dione (= 5,8-dihydroxy-1,4-naphthoquinone).
The hydroxynaphtoquinones (in the particular or the general sense) include many biologically and industrially important compounds, and are a building-block of many medicinal drugs.
From 1,4-naphthoquinone
Due to its symmetry there are only three isomers:
From 1,2-naphthoquinone
From 1,2-naphthoquinone (ortho-naphthoquinone) there are 6 possible isomers:
From 2,3-naphthoquinone
From 2,3-naphthoquinone, also a symmetric molecule there are only three isomers:
From 2,6-naphthoquinone
From the symmetrical 2,6-naphthoquinone (amphi-naphthoquinone) there are only three: