What is the IUPAC name for the molecule shown below?
A) 2-methyl-5-propyl-3-heptyne
B) 5-ethyl-2-methyl-3-octyne
C) 1-isopropyl-3-ethyl-1-hexyne
D) 6-methyl-3-propyl-4-heptyne
E) 4-ethyl-7-methyl-5-octyne

Question

What is the IUPAC name for the molecule shown below? 
A) 2-methyl-5-propyl-3-heptyne 
B) 5-ethyl-2-methyl-3-octyne 
C) 1-isopropyl-3-ethyl-1-hexyne 
D) 6-methyl-3-propyl-4-heptyne 
E) 4-ethyl-7-methyl-5-octyne

Quizplus · Accepted Answer

The longest carbon chain contains 8 carbons, giving the root word octyne. The triple bond starts at the 2nd carbon and contains two methyl groups and an ethyl group as substituents. Therefore, the correct IUPAC name is 5-ethyl-2-methyl-3-octyne.

What Is the IUPAC Name for the Molecule Shown Below