Nomenclature of Aldehydes and Ketones

Aldehydes and ketones are also referred to as carbonyl compounds. These are the classes of organic compounds in which the functional group contains the carbon-oxygen double bond.

Aldehydes have at least one hydrogen atom bonded to the carbonyl group, the other group may be either a hydrogen or an alkyl (or aryl) group. In ketones, the carbonyl group is bonded to two alkyl or aryl groups. The two groups bonded to a ketone may be similar or different resulting in a symmetrical or an unsymmatrical ketone, respectively.

Nomenclature of Aldehydes

In the IUPAC system of nomenclature, aliphatic aldehydesare named as alkanals. The final -e in the name of the corresponding alkane is substituted by -al.

When the -CHO group is attached to a ring, then the compound is called a carbaldehyde.

Nomenclature of Ketones

Ketones are named as alkanones in the IUPAC namenclature. Their names are obtained by replacing final -e in the name of alkane by -one. The carbon chain is numbered in such a way that the carbonyl group gets the lowest number.