The IUPAC name of the compound, `CH_2=underset(CH_3)underset(|)C-CH_2-C-=CH` is

Options

A. 2- Methylpent -1-en-4-yne
B. 4- Methylpent -4-en-1-yne
C. 2- Methylpent -2-en-4-yne
D. 4- Methylpent -2-en-1-yne

Answer

To determine the IUPAC name of the compound `CH_2=underset(CH_3)underset(|)C-CH_2-C-=CH`, we will follow these steps:

### Step 1: Identify the Longest Carbon Chain
- The first step is to identify the longest continuous carbon chain in the compound. In this case, we can see that there are five carbon atoms in the longest chain.

### Step 2: Determine the Functional Groups
- The compound contains a double bond (alkene) and a triple bond (alkyne). The presence of both functional groups will influence the naming.

### Step 3: Number the Carbon Chain
- We need to number the carbon chain in such a way that the double bond and triple bond get the lowest possible numbers.
- If we number from the left, the double bond is at position 1 and the triple bond is at position 4.
- If we number from the right, the double bond is at position 5 and the triple bond is at position 2.
- To give the lowest numbers to the double and triple bonds, we will number from the left.

### Step 4: Identify Substituents
- There is a methyl group (−CH₃) attached to the second carbon of the chain.

### Step 5: Assemble the Name
- The root name for a five-carbon chain is "pent".
- The substituent is a methyl group at position 2, which we denote as "2-methyl".
- The double bond (ene) is at position 1, and the triple bond (yne) is at position 4.
- According to IUPAC naming conventions, we list the double bond before the triple bond in the name.

### Final IUPAC Name
- Putting it all together, the IUPAC name of the compound is **2-methyl-pent-1-ene-4-yne**.