Properties, Synthesis And Uses Of Lactones In Chemical Industry

Compounds obtained from a hydroxyl-carboxylic acid or amino carboxylic acid are due to intra-molecular removal of water from structure are called commonly known as "lactones" or "lactams" [1]. The tautomeric versions of lactams are called lactims. Lactones are categorised as hetero-cycles as a heteroatom (oxygen) has replaced one or more carbon in the ring system. Lactones are typically named similar to the parent acid molecule, where 2 carbon (aceto), 3 (propio), 4 (butyro) and 5 (valero) with suffix of lactones. Lactones with smaller ring system tends to be very reactive as their ring structure is very strained, which makes them difficult to be separated from natural sources. [2] Hence, Laboratory methods are specifically designed for the production of smaller ring structure lactones as well as larger ring structure.

Naturally, and lactones are often observed in nature with exceptions of few macro-cyclic lactones. The production of these types of lactones show case their complete formation from normal acyclic predecessor. Lactones are responsible for their contribution as an odour of various fruits. For example 15-pentadecanolide produces musk like scent for angelica root oil. In cases of bi-cyclic lactones, phthalide is accountable for the smell of celery and coumarin.

Lactones play wide range of role in the nature, some are used as an intermediate in reaction mechanism, while some are used as building blocks in nature for example carbohydrate lactones, which possess five member ring system which is responsible for their stability. [6] The carbohydrate lactones show a relationship between the chirality and reactivity, which changes these types of compounds into useful chemical intermediates towards a diversity of purposes. For example aldono-lactones have been used as a starting material in the production of many types of surfactants and polymers. - Lactones such as 2-oxetanones have been used in synthetic chemistry due to their extensive natural occurrence and biological significance they play an important role of as synthetic intermediates often employed as monomers in biodegradable polymers.