Green Oxidation of Ketones to Lactones with Oxone in Water

Cyclic ketones were quickly and quantitatively converted to 5-, 6- and 7-membered lactones, very important synthons, by treatment with Oxone, a cheap, stable, and non-pollutant oxidizing reagent, in 1M NaH2PO4/Na2HPO4 water solution (pH 7). Under such simple and green conditions, no hydroxyacid was formed thus making unnecessary the adoption of more com-plex and non-ecofriendly procedures previously developed to avoid lactone hydrolysis. With some changes, the method was successfully applied also to water insoluble ketones such as adamantanone, acetophenone, 2-indanone and challenging cy-cloheptanone.