Each of the following reaction is given by tertiary butylbromide except

Options

A. `S_(N)1`
B. `S_(N)2`
C. `E_(1)`
D. `E_(2)`

Answer

To solve the question, "Each of the following reactions is given by tertiary butyl bromide except," we need to analyze the behavior of tertiary butyl bromide (t-BuBr) in different types of reactions. Let's break down the steps:

### Step 1: Understand the Structure of Tertiary Butyl Bromide
Tertiary butyl bromide has the structure:
\[ \text{(CH}_3)_3\text{CBr} \]
This means it has three methyl groups (CH₃) attached to a central carbon atom, which is also bonded to a bromine atom (Br).

**Hint:** Identify the structure of the compound to understand its reactivity.

### Step 2: Identify Reaction Types
Tertiary butyl bromide can undergo various types of reactions:
- **SN1 Reaction**: This occurs when the leaving group (Br) departs first, forming a stable tertiary carbocation, which can then be attacked by a nucleophile.
- **E1 Reaction**: Similar to SN1, but instead of a nucleophile attacking, a base abstracts a proton leading to elimination.
- **E2 Reaction**: This involves a simultaneous removal of the leaving group and a proton by a base, forming a double bond.
- **SN2 Reaction**: This involves a nucleophile attacking the carbon from the opposite side of the leaving group, leading to a single-step mechanism.

**Hint:** Recall the characteristics of each reaction mechanism to determine which one is applicable.

### Step 3: Analyze Each Reaction
1. **SN1 Reaction**: Tertiary butyl bromide can undergo this reaction due to the formation of a stable tertiary carbocation.
2. **E1 Reaction**: Tertiary butyl bromide can also undergo this reaction since it can form a carbocation.
3. **E2 Reaction**: It can participate in this reaction as well, where a base removes a proton while the bromine leaves.
4. **SN2 Reaction**: Tertiary butyl bromide cannot undergo this reaction because the bulky groups create steric hindrance, preventing the nucleophile from effectively attacking the carbon atom.

**Hint:** Compare the steric hindrance in tertiary butyl bromide to understand why SN2 is not feasible.

### Step 4: Conclusion
From the analysis, we conclude that tertiary butyl bromide does not undergo the **SN2 reaction** due to steric hindrance. Therefore, the answer to the question is that the reaction that is not given by tertiary butyl bromide is the **SN2 reaction**.

**Final Answer:** Tertiary butyl bromide does not undergo SN2 reaction.