Nomenclature of Common Functional Groups

The nomenclature is the systematic way of naming organic molecules with a set of rules established by the IUPAC (International Union of Pure and Applied Chemistry). The basic rules of this system are as follows:

• Firstly, identify the longest chain in the organic compound.
• Number the chain of carbon from the side which contains a higher-priority functional group.
• Name the chain with the prefix meth, eth, prop, but, pent, etc with respect to the number of carbon present in the longest chain.
• Name the functional group of the compounds using the appropriate suffixes according to the present functional group.
• If there is more than one functional group present in the chain, the highest priority functional group decides the suffix, and other functional groups are used as a prefix, with alphabetic order (if there is still more than one functional group left after deciding the suffix)

Example: Name the organic compound, CH₃CH₂CHClCOOH.

Solution:

Number the carbon atoms in the given compound, from -COOH side as it is the most reactive group in the given compound. i.e.,

 

As, there are 4 carbon in the longst present chain. It’s name starts with bute, and there is chlorine at second carbon.

Thus, its name is 2-chloro buten-1-oic acid.

Example: What is the IUPAC name of the organic compound CHClBrCH₂CHO?

Solution: 

Number the carbon atoms in the given compound, from -CHO side as it is the most reactive group in the given compound. i.e.,

 

As there are 3 carbon present in the longest chain, it’s name starts with prop root word and there are bromine and cholrine attached to the third carbon.

Thus, name of the given compounds is 3-bromo-3-cholor propen-1-al

Learn more about, Nomenclature of Alcohols, Phenols, and Ethers

Functional Groups if added to hydrocarbons change their functionality and properties. A hydrocarbon is a compound made up of hydrogen and carbon, which can be either saturated or unsaturated. A saturated hydrocarbon is one in which the carbon atoms are joined by only a single bond and an unsaturated hydrocarbon is one in which a double or triple bond between carbon atoms is present. Generally, a saturated hydrocarbon is very less reactive, but when another ‘atom’ or ‘group of atoms’ is attached to it, the resulting molecule becomes highly reactive depending on the attached group. The other ‘atom’ or ‘group of atoms in a carbon compound is called a functional group.