Enone

The general structure of an enone

Methyl vinyl ketone, the simplest enone

An enone is an unsaturated chemical compound or functional group consisting of a conjugated system of an alkene and a ketone. The simplest enone is methyl vinyl ketone (MVK) or CH₂=CHCOCH₃.

As an example, an enone such as a chalcone can be synthesized in a Knoevenagel condensation. In the Meyer-Schuster rearrangement the starting compound is a propargyl alcohol.

Enones undergo reactions vinylogous to the corresponding saturated carbonyl compounds, i.e. conjugate additions. They are electrophilic also at the β-carbon, which can be attacked by nucleophiles. Both direct addition to carbonyl and conjugate addition may occur, depending on conditions. The attack on the carbon produces a more stable compound than direct attack. An example of this is the toxicity, which follows from their ability to alkylate DNA.

An enone is a reactant in the Nazarov cyclization reaction and in the Rauhut-Currier reaction (dimerization).

Related compounds

Enone is not to be confused with Ketene (R₂C=C=O). An enamine is a cousin of an enone, with the carbonyl replaced by an amine group. An enal is the corresponding α,β-unsaturated aldehyde