Choose the correct IUPAC name of the compound
`CH_(3)-overset(" CH"_(3))overset(|)(CH)-overset(" CH"_(3))overset(|)(CH)-C-=C-CH_(3)`

Options

A. 2,3-dimethyl-4-hexyne
B. 4,5-dimethyl-2-hexyne
C. 5-Propyl-2-pentyne
D. 2-Propyl-3-pentyne

Answer

To determine the correct IUPAC name for the given compound, we will follow these steps:

### Step 1: Identify the Longest Carbon Chain
First, we need to identify the longest continuous carbon chain in the compound. The structure provided indicates that there are 6 carbon atoms in the main chain.

**Hint:** Look for the longest continuous chain of carbon atoms that includes the functional groups (like triple bonds).

### Step 2: Number the Carbon Chain
Next, we will number the carbon chain. Since we have a triple bond in the compound, we will start numbering from the end of the chain closest to the triple bond. This ensures that the triple bond receives the lowest possible number.

- Start numbering from the end nearest to the triple bond:
- 1 (C with triple bond)
- 2 (C with triple bond)
- 3 (C)
- 4 (C with methyl group)
- 5 (C with methyl group)
- 6 (C)

**Hint:** Always give the functional groups (like double or triple bonds) the lowest possible numbers in the chain.

### Step 3: Identify Substituents
Now, we will identify any substituents attached to the main carbon chain. In this case, we have two methyl groups attached to the 4th and 5th carbon atoms.

**Hint:** Substituents are groups attached to the main carbon chain; they should be named and numbered according to their position on the chain.

### Step 4: Construct the Name
Now we can construct the name of the compound. The base name is derived from the longest carbon chain, which is hexane (since there are 6 carbons).

- The substituents are 4 and 5 methyl groups, so we write this as "4,5-dimethyl".
- The position of the triple bond is at carbon 2, so we include "2-" before the base name.

Putting it all together, the IUPAC name of the compound is **4,5-dimethyl-2-hexene**.

**Hint:** When writing the full name, always list the substituents in alphabetical order, and include the position of the functional groups.

### Final Answer
The correct IUPAC name of the compound is **4,5-dimethyl-2-hexene**.