Used primarily as an intermediate in organic synthesis, especially in the production of pharmaceuticals and agrochemicals. It serves as an acylating agent to introduce the crotonyl group into various compounds, enhancing reactivity or modifying biological activity. Commonly applied in the synthesis of active pharmaceutical ingredients (APIs) where its α,β-unsaturated structure allows for conjugate addition reactions. Also utilized in the preparation of specialty esters and amides for use in fine chemicals. Due to its reactivity, it is handled under controlled conditions in industrial and laboratory settings.