Självaldolreaktionen

Självaldolreaktionen, sometimes referred to as the self-aldol reaction or intramolecular aldol condensation when applicable, is a type of organic reaction where a single molecule contains both the enolizable carbonyl group (aldehyde or ketone) and the enolate-forming group. In this reaction, a molecule reacts with itself to form a carbon-carbon bond. Typically, it involves the nucleophilic attack of an enolate ion, formed from one part of the molecule, onto a carbonyl group within the same molecule. This leads to the formation of a beta-hydroxy carbonyl compound. Under conditions that favor dehydration, such as heating or the presence of acid or base, the beta-hydroxy carbonyl compound can then undergo an intramolecular dehydration to yield a cyclic alpha,beta-unsaturated carbonyl compound. The feasibility and outcome of a självaldolreaktionen are strongly dependent on the structure of the starting material, particularly the size of the potential ring being formed. Five- and six-membered rings are generally favored due to their thermodynamic stability. The reaction is a specific case of the aldol reaction, emphasizing the self-condensation aspect within a single molecular entity.