Which of the following will be most readily dehydrated in acidic conditions ?

Options

A.
B.
C.
D.

Explanation

To determine which alcohol will be most readily dehydrated under acidic conditions, we need to analyze the stability of the carbocations formed during the dehydration process. Dehydration involves the removal of a water molecule (H2O) from the alcohol, resulting in the formation of an alkene. The stability of the carbocation intermediate plays a crucial role in the dehydration reaction.

### Step-by-Step Solution:

1. **Identify the Alcohols**: We need to identify the structures of the alcohols provided in the options. Each alcohol has a hydroxyl group (–OH) that will be involved in the dehydration reaction.

2. **Understand Dehydration**: Dehydration is the process of removing a water molecule from the alcohol. In acidic conditions, the hydroxyl group (–OH) can be protonated to form a better leaving group (water) and facilitate the formation of a carbocation.

3. **Formation of Carbocations**: When the alcohol is dehydrated, the following steps occur:
- The lone pair of electrons on the oxygen atom of the –OH group donates to a proton (H⁺) from the acid, forming an oxonium ion (–OH2⁺).
- Water (H2O) is then eliminated, leading to the formation of a carbocation.

4. **Evaluate Carbocation Stability**: The stability of the carbocation formed after dehydration is crucial:
- **Tertiary Carbocations** are the most stable due to hyperconjugation and inductive effects.
- **Secondary Carbocations** are less stable than tertiary but more stable than primary.
- **Primary Carbocations** are the least stable.

5. **Analyze Each Option**:
- **Option 1**: Forms a primary carbocation, which is not stable.
- **Option 2**: Forms a secondary carbocation, which is more stable than primary but less stable than tertiary.
- **Option 3**: Forms a tertiary carbocation, which is the most stable and will dehydrate readily.
- **Option 4**: Forms a secondary or primary carbocation depending on the structure, which is less stable than tertiary.

6. **Conclusion**: The alcohol that forms the most stable carbocation will dehydrate most readily. Based on the analysis, **Option 3**, which forms a tertiary carbocation, will be the most readily dehydrated in acidic conditions.

### Final Answer:
**Option 3** will be the most readily dehydrated in acidic conditions.