IUPAC name of the compound is `{:(CH_(3)-CH=C-CH_(3)),(" |"),(" "CH_(2)-CH_(3)):}`

Options

A. 2-ethyl-2-butene
B. 3-ethyl-2-butene
C. 3-methyl-3-pentene
D. 3-methyl-2-pentene

Answer

To determine the IUPAC name of the compound given as `{:(CH_(3)-CH=C-CH_(3)),(" |"),(" "CH_(2)-CH_(3)):}`, we will follow these steps:

### Step 1: Identify the Longest Carbon Chain
First, we need to identify the longest continuous carbon chain in the structure. In this case, we can see that there are two chains: one with 4 carbons (from CH3-CH=C-CH3) and another with 2 carbons (from CH2-CH3). The longest chain is the one with 5 carbons.

### Step 2: Number the Carbon Chain
Next, we need to number the carbon chain. We will number the chain in such a way that the double bond gets the lowest possible number.

- If we number from the left (starting from CH3):
1. CH3 (C1)
2. CH (C2)
3. C (C3)
4. CH3 (C4)
5. CH2 (C5)

The double bond is between C2 and C3.

- If we number from the right (starting from CH2):
1. CH2 (C1)
2. CH3 (C2)
3. C (C3)
4. CH (C4)
5. CH3 (C5)

The double bond is between C3 and C4.

Since we want the double bond to have the lowest number, we will use the first numbering.

### Step 3: Identify Substituents
Now we need to identify any substituents on the main chain. In this case, there is a methyl group (CH3) attached to the third carbon (C3).

### Step 4: Write the IUPAC Name
Now we can write the IUPAC name based on the information we have gathered:
- The main chain is pentene (since it has 5 carbons and a double bond).
- The position of the double bond is between C2 and C3, so we will denote it as 2-pentene.
- There is a methyl group on C3, so we will denote it as 3-methyl.

Putting it all together, the IUPAC name of the compound is **3-methyl-2-pentene**.

### Summary of Steps
1. Identify the longest carbon chain.
2. Number the chain to give the double bond the lowest number.
3. Identify any substituents and their positions.
4. Write the IUPAC name based on the main chain and substituents.