A solution of potically active 1-phenylethanol racemizes in acidified aqueous medium. It is dou to :

Options

A. enolizstion
B. carbonium ion formation
C. carbanion formation
D. reversible oxidation-reduction

Explanation

To solve the question regarding why a solution of optically active 1-phenylethanol racemizes in an acidified aqueous medium, we can break it down into the following steps:

### Step 1: Understand the Structure of 1-Phenylethanol
1-Phenylethanol has the following structure:
- It consists of a phenyl group (C6H5) attached to a carbon that is also bonded to a hydroxyl group (OH) and a methyl group (CH3).
- The structure can be represented as:

```
OH
|
C6H5-C-CH3
```

### Step 2: Identify the Conditions of the Reaction
The reaction occurs in an acidified aqueous medium. This means that there is an excess of H⁺ ions (protons) present in the solution.

### Step 3: Protonation of the Alcohol
In the presence of acid, the hydroxyl group (OH) of 1-phenylethanol can be protonated:
- The oxygen atom in the hydroxyl group has lone pairs that can accept a proton (H⁺), forming an oxonium ion (R-OH₂⁺).

### Step 4: Formation of Carbocation
Once the hydroxyl group is protonated, it becomes a better leaving group. The water molecule (H₂O) can then leave, resulting in the formation of a carbocation:
- The carbocation is a positively charged carbon atom that is formed when the OH₂ group leaves.

```
+
C6H5-C
|
CH3
```

### Step 5: Racemization Process
The carbocation formed is planar and can be attacked by a nucleophile (water in this case) from either side:
- This leads to the formation of both enantiomers (R and S forms) of 1-phenylethanol, resulting in a racemic mixture.

### Step 6: Conclusion
The racemization of optically active 1-phenylethanol in an acidified aqueous medium is due to the formation of a carbocation intermediate, which allows for nucleophilic attack from either side, leading to the formation of both enantiomers.

### Final Answer
The racemization of optically active 1-phenylethanol in an acidified aqueous medium is due to the formation of a carbocation intermediate, which allows for the nucleophilic attack from either side, resulting in a racemic mixture.

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