What is aldol condensation?
When aldehydes and ketones having at least one α-hydrogen are treated with dilute alkali (which act as a catalyst) they form β-hydroxy aldehydes (aldol) or β-hydroxy ketones (ketol) respectively. This reaction is known as aldol condensation.
Explain the mechanism of Aldol condensation.
Aldol condensation is an organic reaction in which an enolate ion reacts with carboxyl compound in order to form a β– hydroxy aldehyde or β– hydroxy ketone.
- Hydroxide functions as a base and therefore moves the acidic a-hydrogen producing the reactive enolate ion. This reaction can be seen as an acid-base reaction.
- The aldehyde is attacked at the electrophilic carbonyl carbon by the nucleophilic enolate ion. This attack is a nucleophilic addition reaction and gives alkoxide intermediate.
- The alkoxide deprotonates water molecule, thereby producing hydroxide and the β–hydroxy aldehyde.
Which reference books can be followed to prepare for aldol condensation?
For studying aldol condensation one can follow the NCERT chemistry textbook part-2 for class 12. The chapter named ‘Aldehydes, Ketones and Carboxylic acids’ in this book contains this process.
What is crossed aldol condensation?
Crossed aldol condensation is a variation of aldol condensation in which two dissimilar carbonyl compounds (each containing alpha hydrogens) undergo the condensation reaction together. In such reactions, up to four different products may be formed.
What is the Aldox process?
The Aldox process is an industrial variation of the aldol condensation reaction for the direct conversion of syngas and propene into 2-ethyl hexanol. This product is formed via the hydroformylation of the reactants into butyraldehyde, its subsequent aldol condensation into 2-ethyl hexenal, and the hydrogenation of this intermediate into 2-ethyl hexanol.