acylketene

An acylketene is a type of organic compound characterized by the presence of a ketene functional group (R2C=C=O) that is also substituted with an acyl group (R-C=O). This means the molecule has the general structure R-C(=O)-C(=C=O)-R'. The carbon atom of the acyl group is bonded to one of the carbons of the ketene moiety. Acylketenes are highly reactive intermediates and are not typically isolated under normal conditions. They are often generated in situ from the decomposition of other compounds, such as acyl azides or oxazolones. The reactivity of acylketenes stems from the cumulative double bonds and the electron-withdrawing nature of the carbonyl groups, making them susceptible to nucleophilic attack and cycloaddition reactions. They readily undergo [2+2] cycloadditions with alkenes and alkynes to form cyclobutanones and cyclobutenones, respectively. Acylketenes can also react with amines and alcohols. Due to their transient nature and high reactivity, acylketenes are important in synthetic organic chemistry for the construction of various cyclic and heterocyclic compounds. Their study often involves trapping experiments to detect and characterize the species formed upon reaction with other molecules.