Hexane-2,5-dione


2,5-Hexanedione is an aliphatic diketone. It is a colorless liquid. In humans, it is a toxic metabolite of hexane and of 2-hexanone.

Symptoms of poisoning

The chronic toxicity of hexane is attributed to hexane-2,5-dione. The symptoms are tingling and cramps in the arms and legs, followed by general muscular weakness. In severe cases, atrophy of the skeletal muscles is observed, along with a loss of coordination and vision problems.
Similar symptoms are observed in animal models. They are associated with a degeneration of the peripheral nervous system, starting with the distal portions of the longer and wider nerve axons.

Mechanism of action

It appears that the neurotoxicity of 2,5-hexanedione resides in its γ-diketone structure since 2,3-, 2,4-hexanedione and 2,6-heptanedione are not neurotoxic, whereas 2,5-heptanedione and 3,6-octanedione and other γ-diketones are.
2,5-Hexanedione reacts with lysine residues in axonal proteins by Schiff base formation followed by cyclization to give pyrroles. Oxidation of the pyrrole residues then causes cross-linking and denaturation of proteins, which perturbs axonal transport and function and causes damage to nerve cells.

Synthesis

2,5-Hexanedione has been prepared in several ways. A common method involves hydrolysis of 2,5-dimethylfuran, a glucose derived heterocycle.

Uses

Acetonylacetone can be used in the synthesis of isocarboxazid, rolgamidine, and mopidralazine. Treatment with P4S10 gives 2,5-dimethylthiophene.