Aldehydes and Ketones
Carboxylic Acids and Derivatives
Alcohols contain a hydroxyl (–OH) group, which substitutes for one or more of the hydrogens in
the hydrocarbon chain.
Alcohols are named by substituting the suffix –ol or by using the prefix hydroxy– if a higher-
priority group is present.
Alcohols have higher priority than double or triple bonds and alkanes.
Common names of alcohols include the name of the carbon chain followed by the word
alcohol. For example, ethyl alcohol is the same compound as ethanol.
Diols contain two hydroxyl groups. They are termed geminal if on the same carbon or vicinal
if on adjacent carbons.
Aldehydes and ketones contain a carbonyl group—a carbon double-bonded to an oxygen.
Aldehydes have the carbonyl group on a terminal carbon that is also attached to a hydrogen
atom.
Aldehydes are named with the suffix –al, or by using the prefix oxo– if a higher-priority group is
present.
Common names of aldehydes include formaldehyde for methanal, acetaldehyde for ethanal,
and propionaldehyde for propanal.
Ketones have the carbonyl group on a nonterminal carbon.
Ketones are named with the suffix –one and share the prefix oxo– if a higher-priority group is
present. Ketones can also be indicated by the prefix keto–.
The common names of ketones are constructed by naming the alkyl groups on either side
alphabetically and adding ketone. For example, 2-butanone is called ethylmethylketone.
Acetone is significant as the smallest ketone. Its IUPAC name is propanone.
Carbonyl-containing compounds (aldehydes, ketones, carboxylic acids, and derivatives) also
create a lettering scheme for carbons. The carbon adjacent to the carbonyl carbon is the α-
carbon.
