ABSTRACT
Enols and enolates nucleophilic derivatives of carbonyl-containing compounds (aldehydes, ketones, esters, and amides) formed with acid or base, respectively. Under basic conditions, asymmetric ketones can selectively form two different enolates depending on the conditions. Enamines are nucleophilic derivatives of aldehydes and ketones formed from the reaction with secondary amines. Enols, enolates, and enamines can be used for the formation of carbon-carbon bonds through substitution of haloalkanes. More important is the use of enolates and enolates in reactions with aldehydes, ketones, and esters. These reactions, known as aldol and Claisen reactions, produce β-hydroxyaldehyde, or β-hydroxyketone, α,β-unsaturated aldehydes (or ketones), and β-ketoesters. These reactions can produce complex structures from rather simple starting materials and are at the core of modern organic synthesis. In this chapter, the details of enol, enolate, and enamine reactions and conjugate addition will be considered along with variations of the aldol and Claisen reactions, including the Henry reaction, Dieckmann reaction, and Robinson annulation.
