Question

What is the name of the following compound?

• A. 2-Ethylbutan-1-ol
• B. 2-Methylpentan-1-ol
• C. 2-Ethylpentan-1-ol
• D. 3-Ethylbutan-4-ol

Answer 1

The correct option is A 2-Ethylbutan-1-ol

$\bullet$ The IUPAC nomenclature is done by determining the main carbon chain which contains the most active functional group.
$\bullet$ The longest hydrocarbon chain in the given compound consists of five carbon atoms, but it is not the main chain because it does not contain the functional group (-OH). The other carbon chain consists of four carbon atoms with -OH group. The carbon attached to the -OH functional group is labeled as 1.
$\bullet$ It is a saturated carbon chain, hence the word root with suffix is butanol. An alkyl group attached to the second carbon atom is 'ethyl' group. Therefore, the correct nomenclature is 2-Ethylbutan-1-ol.




The name 3-ethylbutan-4-ol is not possible because the labeling of the carbon atoms is done with the carbon atom having the highest functional group is given the label 1.