Question

additional practice

1. use the iupac rules to name the following structures.

a. $\mathrm{ch}_{3} \mathrm{chch}_{2} \mathrm{chch}_{2} \mathrm{ch}_{3}$
b. $\mathrm{ch}_{3} \mathrm{cch}_{2} \mathrm{chch}_{3}$
c. $\mathrm{ch}_{3} \mathrm{chch}_{2} \mathrm{ch}_{2} \mathrm{chch}_{2} \mathrm{chch}_{3}$

Explanation:

Step1: Identify the longest carbon chain (parent chain)

For a: The longest chain has 7 carbons (heptane).
For b: The longest chain has 5 carbons (pentane).
For c: The longest chain has 9 carbons (nonane).

Step2: Number the chain

For a: Number from the left - hand side (gives lower locants for substituents).
For b: Number from the left - hand side.
For c: Number from the left - hand side.

Step3: Identify and name substituents

For a: There are two methyl ($-CH_3$) groups at positions 2 and 5.
For b: There are three methyl groups at positions 2, 2, and 4.
For c: There are three methyl groups at positions 2, 6, and 8, and one ethyl ($-CH_2CH_3$) group at position 3.

Step4: Write the name

For a: 2,5 - dimethylheptane.
For b: 2,2,4 - trimethylpentane.
For c: 3 - ethyl - 2,6,8 - trimethylnonane.

Answer:

a. 2,5 - dimethylheptane
b. 2,2,4 - trimethylpentane
c. 3 - ethyl - 2,6,8 - trimethylnonane