What is the IUPAC name of the following compound? (CH
CH
)
COH Multiple Choice 2-Ethylpentan-2-ol 2-Ethylpentan-3-ol 2,2-Diethylbutan-1-ol 3-Ethylpentan-3-ol
The Correct Answer and Explanation is:
The compound you provided is (CH₃CH₂)COH, which represents 2-Ethylpentan-2-ol.
Here’s the explanation for the correct IUPAC name:
- Identify the longest carbon chain:
The longest chain of carbon atoms containing the functional group (hydroxyl group, -OH) is a pentane chain (5 carbon atoms). So, this is a pentanol (alcohol). - Number the chain:
To determine the correct numbering, the functional group (-OH) must be given the lowest possible number. Here, the hydroxyl group is attached to the second carbon atom in the chain, making it 2-pentanol. - Identify the substituents:
The substituent is an ethyl group (-CH₂CH₃), which is attached to the second carbon atom. Therefore, this becomes 2-ethyl. - Combine the name:
Combining the above steps, the correct name is 2-ethylpentan-2-ol, indicating an ethyl group attached to the second carbon atom in a pentane chain with an alcohol group (-OH) also at the second position.
Thus, the correct IUPAC name is 2-Ethylpentan-2-ol.
Why not the other options?
- 2-Ethylpentan-3-ol: This suggests the alcohol group is at the third position, but the given structure has it at the second position.
- 2,2-Diethylbutan-1-ol: This suggests a 4-carbon chain (butane) with two ethyl groups at the second position, which does not match the provided structure.
- 3-Ethylpentan-3-ol: This would place the ethyl group and hydroxyl group at the third position, which again doesn’t match the given compound.
Thus, 2-Ethylpentan-2-ol is the correct answer.
