1,8‐Cineole: Chemical and Biological Oxidation Reactions and Products

The products of chemical and biological oxidation (hydroxy, oxo, and acid derivatives) of 1,8‐cineole (3,3‐dimethyl‐2‐oxabicyclo[2.2.2]octane) are reviewed with a focus on the diverse regio‐ and stereoselectivities obtained from this meso monoterpenic compound abundantly present in eucalyptus leaves. Physical properties (melting‐point and specific rotation values) as well as 1H and 13C NMR spectroscopic data of oxidized derivatives have been exhaustively compiled with particular attention on the clarification of some literature inconsistencies owing to different carbon numbering and stereochemical denominations. Analytical and synthetic methods, and formation as metabolites by plants, microorganisms, and animals are also reviewed together with their presently known biological activities.