thumb|General aldol structure showing the α and 𝛽 positions of carbons relative to the carbonyl. When R" is -H, it is an aldol, when R" is a carbon, it is a ketol.
In organic chemistry, an aldol is a structure consisting of a hydroxy group (-OH) two carbons away from either an aldehyde or a ketone. The name combines the suffix 'ol' from the alcohol and the prefix depending on the carbonyl group, either 'ald' for an aldehyde, or 'ket' for a ketone, in which case it referred to as a 'ketol'. An aldol may also use the term β-hydroxy aldehyde (or β-hydroxy ketone for a ketol). The term "aldol" may refer to 3-hydroxybutanal.
Aldols are the product of a carbon-carbon bond-formation reaction, giving them wide applicability as a precursor for a variety of other compounds.
Synthesis and reactions
center|thumb|555x555px|Possible [[Absolute configuration|stereochemical configurations for chiral aldols. R/S configurations of chiral centers: A: OH is 4R, R-group is 3R B: OH is 4S, R-group is 3S C: OH is 4R, R-group is 3S D: OH is 4S, R-group is 3R]]
Aldols are usually synthesized from an aldol addition reaction using two aldehydes or an aldehyde and a ketone for a ketol. The aldol 3-hydroxybutanal is a precursor to quinaldine, which is a precursor to the dye quinoline Yellow SS.
See also
- Aldol reactions
- Beta hydroxycarboxylic acid