2-Bromo-3,3- dimethylbutane on reaction with aqueous KOH yields X as the major product. X is

Options

A. 2,3,-trimethylpropan-1-ol
B. 2,2-dimethlbutan-3-ol
C. 2,3- dimethylbutan-2-ol
D. 2,2-dimethylpropan-2-ol

Explanation

To solve the question regarding the reaction of 2-Bromo-3,3-dimethylbutane with aqueous KOH, we will follow these steps:

### Step 1: Identify the Structure of 2-Bromo-3,3-dimethylbutane
The molecular structure of 2-bromo-3,3-dimethylbutane can be represented as follows:
- The longest carbon chain contains 4 carbon atoms (butane).
- The bromine atom is attached to the second carbon.
- There are two methyl groups attached to the third carbon.

The structure can be drawn as:
```
CH3
|
CH3-C-CH-CH3
|
Br
```

### Step 2: Determine the Type of Reaction
When 2-bromo-3,3-dimethylbutane reacts with aqueous KOH, it undergoes a nucleophilic substitution reaction. Given that KOH is in aqueous solution, the reaction will likely follow the SN1 mechanism due to the formation of a stable carbocation.

### Step 3: Formation of Carbocation
In the first step of the SN1 mechanism, the bromine atom (a good leaving group) leaves, forming a carbocation. The structure of the carbocation formed is:
```
CH3
|
CH3-C^+-CH-CH3
|
```
This is a secondary carbocation.

### Step 4: Carbocation Rearrangement
To achieve a more stable carbocation, a methyl shift can occur. A methyl group from one of the adjacent carbons can move to the positively charged carbon, leading to a more stable tertiary carbocation:
```
CH3
|
CH3-C-CH3
|
C^+
```

### Step 5: Nucleophilic Attack by OH⁻
The hydroxide ion (OH⁻) from KOH will now attack the carbocation, resulting in the formation of the alcohol:
```
CH3
|
CH3-C-CH3
|
OH
```

### Step 6: Naming the Product
The final product is 2,3-dimethylbutan-2-ol. The numbering starts from the end of the chain closest to the hydroxyl group (OH), giving it the lowest possible number. The structure can be named as follows:
- The longest carbon chain is butane (4 carbons).
- The hydroxyl group is on the second carbon.
- There are two methyl groups on the second and third carbons.

Thus, the name of the product is **2,3-dimethylbutan-2-ol**.

### Conclusion
The major product (X) formed from the reaction of 2-bromo-3,3-dimethylbutane with aqueous KOH is **2,3-dimethylbutan-2-ol**.

---