Butanolide is a chemical compound belonging to the family of lactones. It is a cyclic ester of butyric acid, which is widely used in various industrial applications. However, there are many synonyms for butanolide, including butyrolactone, 4-hydroxybutanolide, delta-butyrolactone, tetrahydrofuran-2-one, and gamma-butyrolactone. These names are used interchangeably in scientific literature and industrial applications, as they refer to the same chemical structure. Butanolides are used in various industries, including pharmaceuticals, plastics, and perfumes, due to their unique chemical properties. They have a wide range of applications in the production of solvents, fragrances, and plasticizers.