Question

What is the IUPAC name of the following Compound?
\[C{{H}_{3}}-CH\left( C{{H}_{3}} \right)-CH\left( C{{H}_{3}} \right)-C{{H}_{2}}-C{{H}_{3}}\]
A.\[3,4-dimethylpentane.\]
B.\[2,3-dimethylpentane.\]
C.\[2-ethyl-3-pentane.\]
D.\[3-ethyl-2-methylbutane.\]

Answer 1

Hint: We know that for this problem, we should know about the general points of the IUPAC naming while naming the compound like the naming of functional groups, alkyl groups, chains, etc. So that we can easily draw the structure of the molecule by using its name.

Complete answer: In chemistry, a symbol is used as an abbreviation to describe an element. The IUPAC stands for International Union of Pure and Applied Chemistry. It has formulated some rules for the systematic nomenclature of organic compounds which are even revised later on for the uniform naming of compounds. The IUPAC has laid down some rules which govern the naming of all the organic compounds. This is necessary so that there is uniform nomenclature to be followed world-wide. The IUPAC name of any molecule consists of three parts: Prefix, stem name and suffix. The rules for nomenclature are as follow as:
The longest chain in the molecule will be the parent chain. So, the first thing one should do is to find the longest carbon chain in the molecule.
\[\underset{\left( 1 \right)}{\mathop{C{{H}_{3}}}}\,-\underset{\left( 2 \right)}{\mathop{CH}}\,\underset{\begin{smallmatrix}
 Position-2 \\
 Methyl~Group
\end{smallmatrix}}{\mathop{\left( C{{H}_{3}} \right)}}\,-\underset{\left( 3 \right)}{\mathop{CH}}\,\underset{\begin{smallmatrix}
 Position-3 \\
 Methyl~Group
\end{smallmatrix}}{\mathop{\left( C{{H}_{3}} \right)}}\,-\underset{\left( 4 \right)}{\mathop{C{{H}_{2}}}}\,-\underset{\left( 5 \right)}{\mathop{C{{H}_{3}}}}\,\]
Find out all the substituents present on the carbon chain. It can be any- from methyl to any alcohol substituent.
Start numbering the parent chain from the end such that the substituent gets the lowest number. This is called the lowest location rule.
If the substituent occurs more than one time, then the prefix di, tri or tetra is being used with the location of the carbon on which it is present.
If more than one substituents are present and they are different. So, these will be named in alphabetical order.
Here the given compound contains single bonds solely, therefore its paraffin. Their square measure two alkyl groups substituted to the parent carbon chain containing five carbon atoms. The listing can take place from the aspect wherever the alkyl group gets the least listing. Therefore listing can take place from left to right. Thus, the IUPAC name of the compound may be given as follow: \[2,3-dimethylpentane.\]
Therefore, the correct answer is option B.

Additional Information: Also the IUPAC nomenclature is needed because earlier every chemist gave its own new name to the molecule it discovered. As a result, one molecule had different names at different places. It was difficult to study them. No one knows whether the molecule discovered by him/her is the new one or the one that has already been discovered. So, the scientist devised some formulations to uniform the naming of compounds.

Note:
Remember that for other functional groups such as carboxylic acid the suffix -oic acid is used, for aldehyde -al is used, etc. The naming of the functional group is also dependent on the priority order of the functional groups.