Write down the IUPAC names of the compounds given.

The IUPAC names of the given compounds with proper numbering of the main chain and the substituents keeping in mind the fact that the numbering is done so as to choose the longest branch of carbon and giving the carbon bearing the substituent or the functional group the lowest number as possible are as follows: -

1. At first we find the longest chain of the carbon atom. Here there are two ways of reaching at the longest chains and both the routes gives the same length i.e. of 6 carbon atom as the longest chain.

2. So, as no double or triple bond is there the word root is hexane.

3. One route starts with the carbon atom labelled a and the other route starts with the carbon atom labelled b. From whichever route we start we get the methyl substituents at the 2^nd and 3^rd carbon atoms.

4. Since two methyl groups are there so the prefix di is added followed by the position of them.

5. Hence, the IUPAC name is 2,3-dimethylhexane.