γ-Lactones are a family oforganic compounds with the formula cyclo-O=COCHRCH₂CH₂. The parent member isγ-butyrolactone (R = H). A commercially important set of γ-lactones are derived from thefree radical addition offatty alcohols andacrylic acid. They are all weakly volatile liquids, which are colorless when pure, but typical samples are not.^[1]

Chemical, biological, and hybrid routes have been developed for these fragrances. Some fungal enzymes hydroxylate fatty acids, leading to the corresponding lactones.^[2] In terms of chemical routes,fatty alcohols undergo free radical addition toacrylic acid, giving hydroxy carboxylic acids, which spontaneously lactonize.^[1]

• Poisson, L. (July 23, 2008). "Characterization of the most odor-active compounds in an American Bourbon whisky by application of the aroma extract dilution analysis".J Agric Food Chem.56 (14):5813–9.doi:10.1021/jf800382m.PMID 18570373.

• Perfume ingredients
• Gamma-lactones