Question

The IUPAC name of phenyl isopentyl ether is

• A. 3-Methylbutoxybenzene
• B. 2-Methylbutoxybenzene
• C. 2-Methylphenoxybutane
• D. 4-Methylbutoxybenzene
• E. 1-Methylbutoxybenzene

Hint:

Ether naming: alkoxy + parent hydrocarbon.

Answer 1

The Correct Option is A

Step 1: Understanding IUPAC Nomenclature for Ethers:
Ethers (R-O-R') are named as alkoxy derivatives of the parent alkane (or arene). The smaller alkyl/aryl group is considered part of the alkoxy group, and the larger group is treated as the parent chain.
Step 2: Identifying the Groups and Parent Chain:
The compound is phenyl isopentyl ether. The two groups attached to the oxygen atom are:
Phenyl group: -C\(_6\)H\(_5\)
Isopentyl group: Also known as 3-methylbutyl. Its structure is -CH\(_2\)CH\(_2\)CH(CH\(_3\))CH\(_3\).
The ether structure is C\(_6\)H\(_5\)-O-CH\(_2\)CH\(_2\)CH(CH\(_3\))CH\(_3\).
The phenyl group has 6 carbons, and the isopentyl group has 5 carbons. According to IUPAC rules for aromatic ethers, the benzene ring is treated as the parent compound. Therefore, the name will be of the form (alkoxy)benzene.
Step 3: Naming the Alkoxy Group:
The alkoxy group is derived from the isopentyl group: -O-CH\(_2\)CH\(_2\)CH(CH\(_3\))CH\(_3\).
To name this group, we number the carbon chain starting from the carbon attached to the oxygen atom.
\[ \text{-O-CH}_2^1\text{-CH}_2^2\text{-CH}^3(\text{CH}_3)\text{-CH}_3^4 \] The parent chain of the alkyl group is butane (4 carbons). There is a methyl substituent on carbon-3.
So, the name of the alkyl group is 3-methylbutyl.
As an alkoxy group, it is named 3-Methylbutoxy.
Step 4: Assembling the Full IUPAC Name:
The alkoxy group is "3-Methylbutoxy" and the parent arene is "benzene".
The complete IUPAC name is 3-Methylbutoxybenzene.