Question

Propose a mechanism for the aldol condensation of cyclohexanone. Do you expect the equilibrium to favor the reactant or the product?

Short answer

Cyclohexanone reacts with the hydroxide ion to form theenolate which is resonance stabilized. Then the enolate acts as a nucleophile and attack on another molecule of cyclohexanone. In the last step, protonation by water gives the aldol product, which is 1’-hydroxybi(cyclohexan)-2-one.

Formation of 1’-hydroxybi(cyclohexan)-2-one

Step-by-step solution

Aldol condensation of cyclohexanone

Cyclohexanone reacts with the hydroxide ion to form theenolate which is resonance stabilized. Then the enolate acts as a nucleophile and attack on another molecule of cyclohexanone. In the last step, protonation by water gives the aldol product, which is 1’-hydroxybi(cyclohexan)-2-one.

Formation of 1’-hydroxybi(cyclohexan)-2-one

Equilibrium in Aldol condensation

Equilibrium in Aldol condensation of ketone recommends forming reactants, not products. The product formed in the aldol condensation is very bulky; thus,there is asignificant hindrance on both carbons with new bonds; therefore, the aldol condensation of cyclohexanone favor reactants at the equilibrium.