Mesityl oxide

Mesityl oxide is a α,β-unsaturated ketone with the formula CH3C(O)CH=C(CH3)2. This compound is a colorless, volatile liquid with a honey-like odor.

Synthesis
It is prepared by the aldol condensation of acetone to give diacetone alcohol, which readily dehydrates to give this compound.


 * [[Image:Acetone mesityl oxide.png|400px]]

Phorone and isophorone may be formed under the same conditions. Isophorone originates via a Michael addition:


 * Isophorone mesityl oxide.png

Phorone is formed by continued aldol condensation:


 * Phoron formation.svg

Uses
Mesityl oxide is used as a solvent and in the production of methyl isobutyl ketone by hydrogenation:
 * Hydrogenation of mesityl oxide to MIBK.png

Further hydrogenation gives 4-methyl-2-pentanol (methyl isobutyl carbinol).

Dimedone is another established use of mesityl oxide.