Ketenes are a class of organic compounds characterized by a functional group containing a carbon-carbon double bond adjacent to a carbonyl group (C=C=O). They are typically reactive and can participate in various chemical reactions, making them useful intermediates in organic synthesis. Ketenes can be generated from the thermal decomposition of certain precursors, such as acyl chlorides or carboxylic acids. These compounds are known for their ability to form cyclopropanes and lactams through cycloaddition reactions. Ketenes also play a role in the production of pharmaceuticals and other fine chemicals, highlighting their importance in both academic research and industrial applications.