Cross aldol condensation occurs when two different aldehydes or ketones react. If both have α-hydrogen atoms, it yields a mixture of four products. The aldol reaction of ethanal and propanal illustrates this when carried out in a mixture.

Aldol and ketol products formed in the Aldol reaction readily lose water to form α, β-unsaturated carbonyl compounds, and this reaction is known as Aldol condensation.

The Aldol reaction involves aldehydes and ketones with at least one α-hydrogen reacting in the presence of dilute alkali to form β-hydroxy aldehydes or β-hydroxy ketones. It is catalyzed by dilute alkali.

Aldehydes are easily oxidized to carboxylic acids by various oxidizing agents, including nitric acid, potassium permanganate, Tollens’ reagent, and Fehlings’ reagent. Ketones, on the other hand, undergo carbon-carbon bond cleavage to form a mixture of carboxylic acids under vigorous oxidation ...

Reduction of the carbonyl group to CH₂ occurs with zinc-amalgam and concentrated hydrochloric acid (Clemmensen reduction) or hydrazine followed by heating with sodium or potassium hydroxide in ethylene glycol (Wolff-Kishner reduction).