What would be the reactant and reagent used to obtain 2,4 - dimethylpentan-3-ol ?

Options

A. Propanal and proyl magnesium bromide
B. 3-Methybutanal and 2- methyl magnesium iodide
C. 2,2-Dimethylpropanone and methyl magnesium iodide
D. 2- Methylpropanal and isopropyl magnesium iodide

Explanation

To obtain 2,4-dimethylpentan-3-ol, we need to identify the appropriate reactant and reagent. Here’s a step-by-step breakdown of the solution:

### Step 1: Identify the Target Compound
The target compound is 2,4-dimethylpentan-3-ol. This indicates that we need a pentane backbone (5 carbon atoms) with two methyl groups on the 2nd and 4th carbon and an alcohol (-OH) group on the 3rd carbon.

### Step 2: Determine the Structure of the Reactant
To synthesize this compound, we can start with a suitable ketone or aldehyde that can be converted into the desired alcohol. A good starting point is 2-methylpropan-2-ol, which has a structure that can be modified to yield the target compound.

### Step 3: Select the Grignard Reagent
To introduce the required carbon chain and functional group, we can use a Grignard reagent. The Grignard reagent we will use is isopropyl magnesium iodide (C3H7MgI), which will add to the carbonyl compound.

### Step 4: Reaction Mechanism
1. **Formation of the Grignard Reagent**: Isopropyl magnesium iodide is formed from isopropyl bromide and magnesium in dry ether.
2. **Nucleophilic Addition**: The Grignard reagent will act as a nucleophile and attack the carbonyl carbon of the ketone (or aldehyde), leading to the formation of an alkoxide intermediate.
3. **Protonation**: Upon hydrolysis (adding water), the alkoxide will be converted to the corresponding alcohol, yielding 2,4-dimethylpentan-3-ol.

### Step 5: Final Product Confirmation
After the reaction, we will confirm that the product formed is indeed 2,4-dimethylpentan-3-ol by checking the structure and ensuring that the methyl groups are on the correct carbon atoms and that the alcohol is on the 3rd carbon.

### Summary of Reactants and Reagents
- **Reactant**: 2-methylpropan-2-ol (or a suitable ketone/aldehyde)
- **Reagent**: Isopropyl magnesium iodide (C3H7MgI)