The correct IUPAC name for the following organic compound is: H?C-CH? H?C-CH-CH?-C?C-CH? A. 5-methyl-2-heptyne B. 5-methyl-2-octyne C. 5-propyl-2-hexyne D. 5-ethyl-2-hexyne

The Correct Answer and Explanation is:
The correct IUPAC name for the given organic compound is:
A. 5-methyl-2-heptyne
Explanation:
To name this organic compound correctly, follow the IUPAC nomenclature rules step by step:
1. Identify the longest continuous carbon chain that includes the triple bond.
From the image:
- Start numbering from the end closest to the triple bond to give the triple bond the lowest possible number.
- The longest carbon chain containing the triple bond has seven carbon atoms (hept-), and the triple bond starts at carbon 2.
2. Identify and name any substituents.
- There is a methyl group (CH₃) attached to the fifth carbon of the chain when counting from the end closest to the triple bond.
3. Combine the name:
- Root name (7 carbon atoms): hept
- Triple bond at carbon 2: 2-yne
- Methyl group at carbon 5: 5-methyl
Putting it all together:
5-methyl-2-heptyne
Why the other choices are incorrect:
- B. 5-methyl-2-octyne: This suggests 8 carbon atoms in the main chain, but the longest chain is only 7 carbons long.
- C. 5-propyl-2-hexyne: There is no propyl group in the structure.
- D. 5-ethyl-2-hexyne: There is no ethyl group present.
Thus, the correct name based on IUPAC rules is:
A. 5-methyl-2-heptyne ✅
