The major product of the following reaction is :
`C_(6)H_(5)CH_(2)-underset(Br)underset(|)overset(CH_(3))overset(|)C=CH_(2)-CH_(3)underset(C_(2)H_(5)OH)overset(C_(2)H_(5)O"N"a)to`

Options

A. `C_(6)H_(5)CH=underset(CH_(3))underset(|)C-CH_(2)CH_(3)`
B. `C_(6)H_(5)CH_(2)-underset(Ch_(3))underset(|)C=CHCH_(3)`
C. `C_(6)H_(5)CH_(2)underset(OC_(2)H_(5))underset(|)overset(CH_(3))overset(|)C-CH_(2)CH_(3)`
D. `C_(6)H_(5)CH_(2)-underset(CH_(2)CH_(3))underset(|)C=CH_(2)`

Answer

To determine the major product of the given reaction, we can follow these steps:

### Step 1: Identify the Reactants
The reactant is a compound with the structure:
- C6H5 (phenyl group)
- CH2 (attached to phenyl)
- CBr (bromine attached to the carbon)
- CH3 (methyl group)
- C=CH2 (alkene)
- CH3 (ethyl group)

### Step 2: Recognize the Reaction Conditions
The reaction is carried out in the presence of sodium ethoxide (C2H5O- Na+), which acts as a strong nucleophile.

### Step 3: Determine the Type of Reaction
Since the carbon attached to bromine is tertiary (due to the presence of the phenyl and methyl groups), we can expect an SN1 mechanism to be favored. Additionally, the presence of a strong base (ethoxide ion) suggests that elimination reactions (E1 or E2) may also occur.

### Step 4: Analyze the Possible Pathways
1. **SN1 Reaction**: The bromine can leave, forming a carbocation. However, since we have a strong base, this pathway may not be the major one.
2. **Dehydrohalogenation (Elimination)**: The ethoxide ion can abstract a proton from the adjacent carbon, leading to the formation of a double bond (alkene) and the elimination of HBr.

### Step 5: Identify the Acidic Hydrogen
In the structure, the hydrogen on the carbon adjacent to the bromine (let's call it Hydrogen A) is more acidic than the hydrogen on the carbon attached to the methyl group (Hydrogen B). This is due to the electron-withdrawing effect of the phenyl group.

### Step 6: Formation of the Major Product
The ethoxide ion will abstract Hydrogen A, leading to the formation of a double bond between the carbon that was attached to bromine and the adjacent carbon. The product will be:
- C6H5-CH=CH-CH2-CH3

### Step 7: Write the Major Product
The major product of the reaction is:
- C6H5-CH=CH-CH2-CH3

### Step 8: Verify the Product
Check the options provided in the question. The correct option matches the structure of the major product identified.

### Final Answer
The major product of the reaction is:
- **C6H5-CH=CH-CH2-CH3**

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