The IUPAC name of `CH_3 - CH = overset(OCH_3)overset(|)C - CH_3 ` is

Options

A. 1-Methoxy-1-methylpropene
B. 2-Methoxybut-2-ene
C. dimethylpropeneether
D. None of these

Explanation

To determine the IUPAC name of the compound `CH3 - CH = OCH3 | C - CH3`, we will follow these steps:

### Step 1: Identify the Structure
The compound consists of:
- A double bond between two carbon atoms.
- A methoxy group (`-OCH3`) attached to one of the carbon atoms involved in the double bond.
- A methyl group (`-CH3`) attached to the carbon chain.

### Step 2: Determine the Longest Carbon Chain
We need to find the longest continuous carbon chain that includes the double bond. In this case, the longest chain consists of four carbon atoms:
1. CH3 (methyl group)
2. CH (part of the double bond)
3. CH (part of the double bond with the methoxy group)
4. CH3 (methyl group)

Thus, the parent chain is butane (4 carbon atoms).

### Step 3: Identify the Functional Groups
- The methoxy group (`-OCH3`) is a substituent.
- The presence of a double bond indicates that the compound is an alkene.

### Step 4: Number the Carbon Chain
We need to number the carbon chain to give the substituents the lowest possible numbers:
- Starting from the end of the chain closest to the double bond, we have:
1. CH3 (1)
2. CH (2) - this carbon has the methoxy group
3. CH (3)
4. CH3 (4)

### Step 5: Assign Positions to Substituents
- The methoxy group is at position 2.
- The double bond starts at position 2 (between carbons 2 and 3).

### Step 6: Write the IUPAC Name
The IUPAC name is constructed by listing the substituents in alphabetical order followed by the name of the parent chain with the position of the double bond:
- The methoxy group is at position 2.
- The parent chain is butene (due to the double bond), and since the double bond starts at carbon 2, we write it as but-2-ene.

Putting it all together, the IUPAC name of the compound is:
**2-methoxybut-2-ene**

### Summary of Steps:
1. Identify the structure of the compound.
2. Determine the longest carbon chain.
3. Identify functional groups.
4. Number the carbon chain.
5. Assign positions to substituents.
6. Write the IUPAC name.