Isophorone is an α,β-Unsaturated cyclic ketone, a colorless to yellowish liquid with characteristic smell, that is used as a solvent

Solvent

A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...

 and as an intermediate in organic synthesis

Organic synthesis

Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...

. Isophorone also occurs naturally in cranberries

Cranberry

Cranberries are a group of evergreen dwarf shrubs or trailing vines in the subgenus Oxycoccus of the genus Vaccinium. In some methods of classification, Oxycoccus is regarded as a genus in its own right...

.

Production

Isophorone can be manufactured by catalyzed self-condensation

Self-condensation

Self-condensation is an organic reaction in which a chemical compound containing a carbonyl group acts both as the electrophile and the nucleophile in an aldol condensation...

 of acetone

Acetone

Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...

.
Mesityl oxide

Mesityl oxide

Mesityl oxide is a α,β-Unsaturated ketone with the formula CH3CCH=C2. This compound is a colorless, volatile liquid with a strong peppermint odor.-Synthesis:...

 is the initial product of the self-aldol condensation of acetone. The mesityl oxide

Mesityl oxide

Mesityl oxide is a α,β-Unsaturated ketone with the formula CH3CCH=C2. This compound is a colorless, volatile liquid with a strong peppermint odor.-Synthesis:...

 formed can react further with acetone via a Michael reaction

Michael reaction

The Michael reaction or Michael addition is the nucleophilic addition of a carbanion or another nucleophile to an alpha, beta unsaturated carbonyl compound. It belongs to the larger class of conjugate additions. This is one of the most useful methods for the mild formation of C-C bonds...

 and subsequent intramolecular aldol condensation to eventually obtain the six-membered ring of isophorone. This is an example of the Robinson annulation

Robinson annulation

The Robinson annulation is an organic reaction used to create a six-member ring α,β-unsaturated cyclic ketone, using a ketone and methyl vinyl ketone...

. The yield of the two compounds depends on the reaction conditions.

History

The use of isophorone as a solvent resulted from the search for ways to dispose of or recycle acetone

Acetone

Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...

, which is a waste product of phenol

Phenol

Phenol, also known as carbolic acid, phenic acid, is an organic compound with the chemical formula C6H5OH. It is a white crystalline solid. The molecule consists of a phenyl , bonded to a hydroxyl group. It is produced on a large scale as a precursor to many materials and useful compounds...

 synthesis by the Hock method.

Uses

Isophorone is used as a solvent in some printing inks, paints, lacquers, adhesives, copolymers, coatings, finishings and pesticides. It is also used as a chemical intermediate and as an ingredient in wood preservatives and floor sealants.