Write the IUPAC name of the following compound \(C_6H_5-O-(CH_2)_6-CH_3\)

1-Phenoxyheptane

The correct answer is option 2. 1-Phenoxyheptane.

Let us break down the structure to find the correct IUPAC name for the compound \(C_6H_5-O-(CH_2)_6-CH_3\).

\(C_6H_5-O\): This part of the molecule represents a phenoxy group. The phenoxy group comes from phenol, where a hydroxyl group (-OH) is replaced by an alkyl or alkoxy group through an oxygen atom. So, \(C_6H_5-O\) means a benzene ring (phenyl group, \(C_6H_5-\)) attached to an oxygen atom.

\((CH_2)_6-CH_3\): This is a linear chain consisting of seven carbon atoms (hexamethylene + methyl group). In total, it forms heptane, an unbranched alkyl chain.

The IUPAC rules for naming ethers involve:

Identifying the alkyl or aryl group attached to the oxygen atom.

Naming the longest carbon chain attached to the oxygen atom.

Here is how we apply those rules:

i. The oxygen atom connects a phenyl group and a heptane chain.

ii. The longest chain is the heptane chain \((CH_2)_6-CH_3\), which has 7 carbon atoms. Since the oxygen atom is connected to the first carbon of this chain, the phenyl group is attached at position 1 of the heptane chain.

iii. The prefix "phenoxy-" is used because the oxygen atom is attached to the phenyl group.

Therefore, the compound is named 1-Phenoxyheptane, indicating that the phenoxy group is attached to the first carbon of the heptane chain

Why Other Options Are Incorrect:

2-Methoxyheptane: This implies a methoxy group (-OCH₃) is attached at the second carbon of a heptane chain. However, the group attached is a phenoxy group, not a methoxy group.

1-Benzoylheptane: This name suggests a benzoyl group (-C₆H₅C=O) is attached to the heptane chain. In the given compound, there is no carbonyl group (C=O) involved, so this name is incorrect.

Methylbenzyl ether: This suggests a structure where a methyl group and a benzyl group are connected through an oxygen atom (CH₃-O-CH₂-C₆H₅). However, the structure here involves a phenoxy group and a heptane chain, not a methylbenzyl structure

Conclusion: The correct IUPAC name is 1-Phenoxyheptane, which correctly describes the structure where a phenoxy group is attached to the first carbon of a heptane chain.

Thus, the correct answer is 2. 1-Phenoxyheptane.