ketone An organic compound containing a nonterminal carbonyl, C=O group. The simplest ketone is acetone. Ketones may be aliphatic, aromatic, cyclic, or mixed. Ketones may be obtained by oxidation of secondary alocohols. Aromatic and mixed ketones are usually prepared by Friedel-Crafts reactions using acyl halides. Aliphatic ketones are usually liquids and aromatic ketones solids; they have etheral or aromatic odors. They are reduced to secondary alcoholes but are resistant to oxidation and give mixtures of acids and other products when strongly oxidized. They form oximes with hydroxylamine, hydrazones with hydrazine, and semicarbazones with semicarbazide. Isonitrosoketones are formed by the action of sodium nitrite. The cyclic ketones have the carbon of the carbonyl group as part of a ring. They are formed by the dry distillation of the calcium or barium salts of acids or by passing the acids over ThO2 at 400°C. Related category ORGANIC CHEMISTRY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |