The conversion of `2-`methylpropan`-1-`ol to `2-`methylpropan`-2-`ol is

Options

A. elimination reaction
B. rearrangement reaction
C. addition reaction
D. substitution reaction

Answer

To convert 2-methylpropan-1-ol to 2-methylpropan-2-ol, we will follow a series of steps that involve a rearrangement reaction. Here’s a step-by-step breakdown of the process:

### Step 1: Identify the Structures
- **2-methylpropan-1-ol** has the following structure:
- CH3-CH(OH)-CH(CH3)-CH3
- **2-methylpropan-2-ol** has the following structure:
- CH3-C(OH)(CH3)-CH3

### Step 2: Protonation of the Alcohol
- The hydroxyl group (-OH) in 2-methylpropan-1-ol can be protonated using a dilute acid like H2SO4. This step enhances the leaving ability of the -OH group.
- The structure after protonation will be:
- CH3-CH(OH2+)-CH(CH3)-CH3

### Step 3: Formation of Carbocation
- Upon protonation, the -OH2+ group can leave as water (H2O), leading to the formation of a carbocation.
- The resulting carbocation is:
- CH3-CH(+)-CH(CH3)-CH3

### Step 4: Hydride Shift
- To stabilize the carbocation, a hydride shift occurs. A hydrogen atom from the adjacent carbon (the one with the CH3 group) shifts to the positively charged carbon.
- This results in the formation of a more stable tertiary carbocation:
- CH3-C(+)(CH3)-CH3

### Step 5: Nucleophilic Attack
- The oxygen from the water molecule (which was eliminated earlier) can now attack the carbocation, leading to the formation of 2-methylpropan-2-ol.
- The final product is:
- CH3-C(OH)(CH3)-CH3

### Conclusion
The conversion of 2-methylpropan-1-ol to 2-methylpropan-2-ol involves a rearrangement reaction, specifically through the formation of a more stable carbocation via a hydride shift.