Question

The correct IUPAC name of the following compound is :

• A. 2,4-dimethyl- 3-ethyl-pentane
• B. 3-ethyl-2,4-dimethylpentane
• C. 2-ethyl-3-isopropylpentane
• D. 2-methyl-3propylbutane

Answer 1

The correct option is B 3-ethyl-2,4-dimethylpentane

1. The longest continuous carbon chain in the molecule and this chain is called the parent/ main/principal chain.

2. When chains of equal lengths are competing for selection then that chain is selected which has more number of substituents/branches.

3. When the number of substituents are same, then the substituents at the nearest positions from the either end is preferred for parent chain selection.

4. If two substituents are found in equivalent positions, then the one coming first in the alphabetical order is given the lower number.

5. When both directions lead to a tie in the lowest number, choose the direction that gives the lowest possible number to the maximum number of substituents

6. If the same substituent occurs more than once in the molecule, then prefix di (for two), tri (for three), tetra(for four) are used to indicate how many times it appears.



The correct IUPAC name of the above structure is:
3-ethyl-2,4-dimethylpentane