monoketones

Monoketones are organic compounds that contain a single ketone functional group, defined by a carbonyl carbon (C=O) bonded to two carbon substituents. The general structure is R-CO-R′, where R and R′ are alkyl or aryl groups. This class is distinct from diketones, which have two carbonyl groups, and from aldehydes, which feature a formyl group instead of a ketone. The simplest example is acetone (propan-2-one). Other common monoketones include methyl ethyl ketone (2-butanone), acetophenone (1-phenylethanone), propiophenone (1-phenyl-1-propanone), and benzophenone (diphenyl ketone).

Monoketones are prepared by oxidation of secondary alcohols, or by acylation methods such as Friedel-Crafts acylation of arenes or oxidation of suitable arenes and ketones. They can also arise from oxidation of secondary alcohols that are otherwise functionalized. Industrial routes vary with substituents and target structures.

Physically, ketones are moderately polar; their boiling points correlate with molecular weight. Some monoketones, like acetone, are miscible with water, while larger aryl ketones are less soluble. They serve as important solvents and chemical intermediates. Acetone is widely used as a laboratory and industrial solvent; methyl ethyl ketone is employed in coatings and cleaning formulations; aromatic ketones such as acetophenone and benzophenone are common in fragrance chemistry and as synthesis precursors.

Chemically, the carbonyl carbon in monoketones undergoes typical ketone reactions: nucleophilic addition to form alcohol derivatives, enolate chemistry, and reductions to secondary alcohols. Ketones can participate in aldol condensations with other carbonyl compounds under basic catalysis; alpha-halogenation and oxidation can further diversify their chemistry.

Safety: many monoketones are flammable and should be handled with standard precautions; acetone is highly volatile. See also: diketones, polyketones, aldehydes.