Aldolisation is a key part of the oxo alcohols process where two aldehydes combine to produce a larger aldehyde which is then converted to an alcohol by hydrogenation.
2-ethylhexanol (2-EH) is produced from normal-butyraldehyde in two reaction steps.
The first step is the aldolisation of normal-butyraldehyde to butyraldol and dehydration of butyraldol to produce 2-ethyl 3-propyl acrolein (EPA). The aldolisation and dehydration reactions are conducted in the presence of aqueous caustic soda at 120°C:
In the Davy oxo alcohols process, a hydroformylation step then follows to yield product alcohol.