Dihydroxynaphthoquinone
A dihydroxynaphthoquinone is any of several organic compounds that can be viewed as derivatives of naphthoquinone through replacement of two hydrogen atoms by hydroxyl groups.
The unqualified term "dihydroxynaphthoquinone" usually means a derivative of 1,4-naphthoquinone. Other dihydroxy- compounds can be derived from the two other known isomers, 1,2-naphthoquinone and 2,6-naphthoquinone.
Isomers
From 1,4-naphthoquinone
Due to the symmetry of the parent quinone, there are only nine distinct isomers of dihydroxy-1,4-naphthoquinone:- 2,3-Dihydroxy-1,4-naphthoquinone.
- 2,5-Dihydroxy-1,4-naphthoquinone.
- 2,6-Dihydroxy-1,4-naphthoquinone.
- 2,7-Dihydroxy-1,4-naphthoquinone.
- 2,8-Dihydroxy-1,4-naphthoquinone.
- 5,6-Dihydroxy-1,4-naphthoquinone.
- 5,7-Dihydroxy-1,4-naphthoquinone.
- 5,8-Dihydroxy-1,4-naphthoquinone.
- 6,7-Dihydroxy-1,4-naphthoquinone.
From 1,2-naphthoquinone
From 1,2-naphthoquinone there are 12 possible dihydroxy- isomers:- 3,4-Dihydroxy-1,2-naphthoquinone
- 3,5-Dihydroxy-1,2-naphthoquinone
- 3,6-Dihydroxy-1,2-naphthoquinone
- 3,7-Dihydroxy-1,2-naphthoquinone
- 3,8-Dihydroxy-1,2-naphthoquinone
- 4,5-Dihydroxy-1,2-naphthoquinone
- 4,6-Dihydroxy-1,2-naphthoquinone
- 4,7-Dihydroxy-1,2-naphthoquinone
- 4,8-Dihydroxy-1,2-naphthoquinone
- 5,6-Dihydroxy-1,2-naphthoquinone
- 5,7-Dihydroxy-1,2-naphthoquinone
- 5,8-Dihydroxy-1,2-naphthoquinone
- 6,7-Dihydroxy-1,2-naphthoquinone
- 6,8-Dihydroxy-1,2-naphthoquinone
- 7,8-Dihydroxy-1,2-naphthoquinone
From 2,6-naphthoquinone
From the symmetrical 2,6-naphthoquinone there are only nine dihydroxy- isomers:- 1,3-Dihydroxy-2,6-naphthoquinone
- 1,4-Dihydroxy-2,6-naphthoquinone
- 1,5-Dihydroxy-2,6-naphthoquinone
- 1,7-Dihydroxy-2,6-naphthoquinone
- 1,8-Dihydroxy-2,6-naphthoquinone
- 3,4-Dihydroxy-2,6-naphthoquinone
- 3,7-Dihydroxy-2,6-naphthoquinone
- 3,8-Dihydroxy-2,6-naphthoquinone
- 4,8-Dihydroxy-2,6-naphthoquinone