Answer
The more common name for the ( 3-methylbutyl ) group is: Isoamyl group.
Structure: $CH_3CH_2CH(CH_3)CH_2-$
Work Step by Step
1. Write the biggest carbon chain, and number its carbons:
- It is: "butyl", so we must draw this chain: $^1CH_3 − \space ^2CH_3 − \space ^3 CH_3 − \space^4 CH_2−$
2. Now, add the other groups:
- Since it is represented by: "3 -methyl", we should attach a methyl groups ($CH_3−$) to the third carbon of the chain, which will lose one hydrogen to do such thing.
- The final chemical formula is: $CH_3CH_2CH(CH_3)CH_2-$
3. Finally, name it properly:
- The name is given in the exercise: "isoamyl group"