An aldol condensation is an organic reaction in which an enol or an enolate ion reacts with a carbonyl compound to form a β-hydroxyaldehyde or β-hydroxyketone, followed by a dehydration to give a conjugated enone.
Aldol condensations are important in organic synthesis, providing a good way to form carbon–carbon bonds. The Robinson annulation reaction sequence features an aldol condensation; the Wieland-Miescher ketone product is an important starting material for many organic syntheses. Aldol condensations are also commonly discussed in university level organic chemistry classes as a good bond-forming reaction that demonstrates important reaction mechanisms. In its usual form, it involves the nucleophilic addition of a ketone enolate to an aldehyde to form a β-hydroxy ketone, or "aldol" (aldehyde + alcohol), a structural unit found in many naturally occurring molecules and pharmaceuticals.
The name aldol condensation is also commonly used, especially in biochemistry, to refer to just the first (addition) stage of the process—the aldol reaction itself—as catalyzed by aldolases. However, the aldol reaction is not formally a condensation reaction because it does not involve the loss of a small molecule.
The reactions between a ketone and a carbonyl compound lacking an alpha-Hydrogen(Cross Aldol condensation) is called Claisen-Schmidt condensation. These reactions are named after two of its pioneering investigators Rainer Ludwig Claisen and J. G. Schmidt, who independently published on this topic in 1880 and 1881. An example is the synthesis of dibenzylideneacetone.
Other articles related to "aldol condensation, condensation, aldol":
... and campholenic aldehyde react in an Aldol condensation ... Occasionally an aldol condensation is buried in a multistep reaction or in catalytic cycle such as the one sketched below In this reaction an alkynal ...
... 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 ... It is also called a symmetrical aldol condensation as opposed to a mixed aldol condensation in which the electrophile and nucleophile are different ... an undesirable, but spontaneous and favored side-reaction of mixed aldol condensation, and special precautions are needed to prevent it ...
Famous quotes containing the word condensation:
“Entification begins at arms length; the points of condensation in the primordial conceptual scheme are things glimpsed, not glimpses.”
—Willard Van Orman Quine (b. 1908)