The system of assigning a name to a compound is known as nomenclature. There are two systems for naming organic compounds
- Common or trivial system
- IUPAC system
The trivial names are given on the basis of the source and certain properties of organic compounds.
Ex: Citric acid is named, as it is found in citrus fruits.
In the year 1947 the IUPAC that is the International Union of Pure and Applied Chemistry system of naming compounds was first developed.
The IUPAC system is a systematic nomenclature in which the name of a compound correlates to its molecular structure.
The IUPAC name of an organic compound consists of three parts the word root, the suffix and the prefix.
The word root indicates the number of Carbon atoms present in the selected longest chain.
| Name of the
| Root Word
A primary suffix is added to the end of the root word. It indicates whether a compound is saturated (or) unsaturated.
The three primary suffixes are, “ane” for alkane, “ene” for alkene and “yne” for alkyne.
A primary prefix is used to differentiate acyclic and cyclic compounds. But the rules for using these are slightly different.
Ex: In cyclic compounds, the prefix cyclo is added before the word root.
A secondary suffix indicates the nature of the functional group present in a compound.
| Organic Compound
|| Functional Group
|| Secondary Suffix
| Carboxylic acid
|| -oic aid
| Acid amides
| Acid chlorides
|| -oyl chloride
In the IUPAC system some groups are not considered as functional groups, they treated as substituent groups. In such cases, the substituent acts as the secondary prefix