Question

The correct IUPAC name of 2-Ethylpent-3-yne is:

• A. 3-Methylhex-4-yne
• B. 4-Ethylpent-2-yne
• C. 4-Methylhex-2-yne
• D. None of these

Answer 1

The correct option is C 4-Methylhex-2-yne

Numbering of carbon is done so as the principal functional group gets the lowest locant on the longest carbon skeleton. In the molecule 2-Ethylpent-3-yne, triple bond is the main functional group hence the numbering can be done as follow:


so the correct name is 4-Methylhex-2-yne.