Gammalactone

Gammalactone, commonly written gamma-lactone, is a gamma-lactone, a five-membered cyclic ester formed by intramolecular esterification of a gamma-hydroxy acid. The ring comprises four carbon atoms and one oxygen, with the ester linkage closing the ring.

Natural occurrence and notable members: Gamma-lactones occur in a variety of natural products, including fruits and essential oils. Notable members include gamma-nonalactone, which has a coconut-like aroma, and gamma-decalactone, known for peachy, fruity notes. The sensory properties of individual gamma-lactones depend on the side chains and ring size.

Production and chemistry: Gamma-lactones are typically prepared by cyclization (lactonization) of gamma-hydroxy acids or related precursors under dehydrating conditions. Industrially important examples include gamma-valerolactone (GVL), derived from levulinic acid, which is produced and marketed as a renewable solvent and a versatile chemical intermediate.

Applications and safety: In the flavors and fragrances industry, gamma-lactones contribute characteristic fruity notes, such as coconut and peach, and are used to flavor foods and craft scents. Gamma-valerolactone is valued as a green solvent for use in polymerization, extraction, and other chemical processes. As with many organic esters, gamma-lactones generally exhibit low acute toxicity, but standard safety practices apply for handling, storage, and exposure to vapors or high concentrations.