Question

Write the IUPAC name of ${\left( {{\text{C}}{{\text{H}}_{\text{3}}}} \right)_{\text{2}}}{\text{CHCH(Cl)C}}{{\text{H}}_{\text{3}}}$.

Answer 1

Hint: The name of alkane includes all substituents arranged in alphabetical order with their position and the name of the parent chain with the position of the double bond. There are some rules which must be followed by naming an alkane. Let us discuss this.

Complete step by step answer:
The IUPAC rules are used for naming the alkane.
The IUPAC rules for the naming of alkane are as follows:
Determine the longest carbon chain and determine the substituents attached to the chain.
If two same long chains are present then select the more substituted chain.
Give the numbering to the carbon atoms of the chains so all the substituents get the lowest numbering.
Arrange the substituents in alphabetical order with their position in the chain.
If the same substituent is present more than one, then add ‘di’ for two, ‘tri’ for three, and so on.
Select the longest parent chain as follows:
The longest carbon chain is of four carbon atoms. The name of five carbon atoms having alkane is ‘butane.
Determine the substituents as follows:
The longest chain has one chloride group and one methyl group.
Give the numbering to the chain as follows:

So, the chloride group is present at carbon-2 and the methyl group is present at carbon-3.
Arrange the substituents in alphabetical order so the name of the compound is of 2-chloro-3-methylbutane.

Therefore, the name of the structure is of 2-chloro-3-methylbutane.

Note: In the molecule, the numbering is given from left to right and the substituents are getting the positions and 3. If the numbering is given from right to left, the substituents will get positions 2 and 3 so, from both sides the numbering is the same. In this the numbering is decided on the basis of substituents. According to alphabetical order, chlorine substituents will come first so, it will get the lowest numbering.