What is the IUPAC name for the molecule shown below?
A) 4-ethyl-2-pentyne
B) 2-ethyl-3-pentyne
C) 3-methyl-4-hexyne
D) 4-methyl-2-hexyne
E) sec-Butylpropyne

Question

What is the IUPAC name for the molecule shown below? 
A) 4-ethyl-2-pentyne 
B) 2-ethyl-3-pentyne 
C) 3-methyl-4-hexyne 
D) 4-methyl-2-hexyne 
E) sec-Butylpropyne

Quizplus · Accepted Answer

The longest carbon chain in the molecule has 6 carbons, so the root name of the molecule is hexyne. The triple bond is located between carbons 2 and 3 and there is a methyl group on carbon 4 and an ethyl group on carbon 2. Therefore, the correct IUPAC name is 4-methyl-2-hexyne. The other answer choices are incorrect because they do not correctly describe the location of the substituents on the hexyne chain.

What Is the IUPAC Name for the Molecule Shown Below