Question

The $IUPAC$ name of the following compound is:

A: $4,6 - $dimethylheptane
B: $1,3,5 - $trimethylhexane
C: $2,4 - $dimethylheptane
D: $2,4,6 - $trimethylhexane

Answer 1

Hint: There are some rules on the basis of which names are given to the organic compounds. These names are decided on the basis of IUPAC system. In this system, the prefix of the compound name indicates the number of carbon atoms and the suffix of the compound indicates the number of bonds between the carbon atoms.

Complete step by step answer:
In this question we have to find the $IUPAC$ name of,

 In this compound there are seven carbon atoms in the main chain (chain that contains the maximum number of carbon atoms is considered as the main chain but if a functional group is present then it may change) and there are two methyl groups in this compound. Since there are seven carbon atoms in the main chain, prefix hept will be used. Suffix ane is used to represent single bonds. Now we have to mention the position of two methyl groups in the compound.
If we start numbering from the left side then the methyl groups are present at fourth and sixth carbon atoms but if we start numbering from right side then the carbon atoms are present at the second and fourth carbon atom. Since the first methyl group gets the lowest number from the right side the numbering will start from the right side.
Now, the position of the methyl group will be represented as, $2,4 - $dimethyl (there are two methyl groups, so word di is used before methyl). So, the name of the compound is $2,4 - $dimethylheptane.
So, the correct answer is option C.


Note:
 In this case methyl groups were getting different numbers from different sides, so we started numbering from the side where the first methyl group (from that side) gets the lowest number. But if methyl groups were at the same position from both sides then we could start numbering from any side.