`Ph-C-=C-Ph overset(Na//NH_3)toAoverset(HC Cl//H^+)toB`
The product B is

Options

A.
B.
C.
D. B and C both

Explanation

To solve the given question, we will follow these steps:

### Step 1: Identify the starting compound
The starting compound is Ph-C≡C-Ph, which is a symmetrical alkyne (1,2-diphenylacetylene).

### Step 2: Perform Birch reduction
The first reaction involves the Birch reduction using sodium (Na) in liquid ammonia (NH₃). The Birch reduction of an alkyne results in the formation of a trans-alkene.

For our compound:
- The alkyne Ph-C≡C-Ph will be converted to trans-stilbene (trans-1,2-diphenylethylene).
- The structure of trans-stilbene can be represented as:
Ph-CH=CH-Ph, where the phenyl (Ph) groups are on opposite sides of the double bond.

### Step 3: React with HOCl
The next step involves the reaction of the trans-alkene with HOCl (hypochlorous acid). The reaction of an alkene with HOCl leads to the formation of a halohydrin.

In this case:
- The trans-alkene will react with HOCl, where the chlorine (Cl) will add to one carbon of the double bond and a hydroxyl group (OH) will add to the other carbon.
- The addition occurs in a way that maintains the trans configuration, resulting in the formation of a 1,2-dichloro-1-phenylethanol.

### Step 4: Identify the final product
The final product (B) after the reaction with HOCl will be:
- Ph-CH(Cl)-CH(OH)-Ph, where one carbon has a chlorine atom and the other has a hydroxyl group.

### Final Answer
The product B is **Ph-CH(Cl)-CH(OH)-Ph**.

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