Question

What is the name of the compound ${\text{C}}{{\text{H}}_3}{\text{C}}{{\text{H}}_2}{\text{CH(C}}{{\text{H}}_3}{\text{)C}}{{\text{H}}_2}{\text{OH}}$ ?
(A) $2 - {\text{methylbutanol}}$
(B) $3 - {\text{methylbutanol}}$
(C) $2 - {\text{methylpentanol}}$
(D) Pentanol

Answer 1

The IUPAC nomenclature of organic chemistry is a method of naming organic chemical compounds as recommended by IUPAC. Prefixes, suffixes and infixes are used to describe the type and the position of the functional group present in a compound.

Complete answer:
To name an organic compound we have to follow some steps. First, identify the parent carbon chain. Choose the chain such that it has the maximum number of substituents of the suffix functional group. If more than one functional group is present in the compound, the functional group with the highest precedence should be used. It should have the maximum number of multiple bonds in it. In the compound, ${\text{C}}{{\text{H}}_3}{\text{C}}{{\text{H}}_2}{\text{CH(C}}{{\text{H}}_3}{\text{)C}}{{\text{H}}_2}{\text{OH}}$ the parent carbon chain consists of four carbon atoms. So, it is called ${\text{ - but}}$ . The functional group present is alcohol, so the suffix will be ${\text{-ol}}$ . There is one side chain attached to the parent carbon chain i.e. methyl group attached to the second carbon atom of the parent chain. Here, the numbering starts from the carbon attached to the functional group alcohol. So, the name of the compound will be $2 - {\text{methylbutanol}}$ .
Therefore, option A is the correct answer.

Note:
To number the carbon atoms present in the parent chain, first number the chain in both directions and choose the numbering which gives the substituents the lowest numbers. If there are multiple substituents in a compound, commas should be put between the numbers.