[4] Certain diketenes with two aliphatic chains, such as alkyl ketene dimers (AKDs), are used industrially to improve hydrophobicity in paper.

An example is the reaction with 2-aminoindane:[6] Diketene is an important industrial intermediate used for the production of acetoacetate esters and amides as well as substituted 1-phenyl-3-methylpyrazolones.

Besides the rosin resins with about 60% share of world consumption, long chain diketenes called alkylketene dimers (AKD) are with 16% share the most important synthetic paper sizes, they are usually used in concentrations of 0.15%, meaning 1.5 kg solid AKD/t paper.

With methylamine diketene reacts to give N,N'-dimethylacetoacetamide, a precursor to the (controversial) insecticide monocrotophos.

The industrial synthesis of the sweetener acesulfam-K is based on the reaction of diketene with sulfamic acid and cyclization by sulfur trioxide (SO3).