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. When the nucleophile is an hydride the reaction is called conjugate reduction.