RCOCH3

RCOCH3 denotes a class of organic compounds in which a carbonyl group (C=O) is bonded to a methyl group on one side and an R group on the other. These are commonly called methyl ketones, a subset of ketones where one substituent is a methyl group. The simplest member is acetone (propan-2-one), where R is a methyl group. Other examples include acetophenone (Ph-CO-CH3), where the carbonyl is attached to a phenyl ring.

Structure and properties: In these molecules the carbonyl is polar and the adjacent (alpha) carbon on the methyl side is enolizable, enabling typical ketone chemistry. This class spans a range of physical properties from volatile liquids to solids, generally with moderate to high polarity relative to hydrocarbons. Their solubility in water and boiling points depend on the size and nature of the R group.

Synthesis and reactions: A common method to prepare methyl ketones is the oxidation of secondary alcohols of the form R-CH(OH)-CH3, which yields R-CO-CH3. Methyl ketones can undergo enolate chemistry: alpha-halogenation to form alpha-halo ketones and aldol reactions with aldehydes or other ketones to give β-hydroxy ketones, which can dehydrate to enones. Enolate formation also enables various nucleophilic additions and condensations in organic synthesis.

Applications: Methyl ketones serve as versatile intermediates in organic synthesis, including pharmaceutical and fragrance chemistry. They are also used as solvents and reagents in various industrial processes. Safety and handling follow standard ketone guidelines: flammable and can be irritant.

See also: ketones, enolates, aldol condensation.