What is the final product of the reaction?
`(CH_3)_(2) = CHCH_2CH_(3) overset((i) BH_3//THF)(rarr)overset(PCC)(rarr) underset((ii)H_2O^+)overset((i) CH_3MgBr)(rarr)`

Options

A. 2,3-dimenthyl pentan - 3 - ol
B. 2,4 - dimethyl pentane - 3-ol
C. 2,3 - dimethyl pentan - 2- ol
D. 2,2-dimethyl pentan-3-ol

Answer

To determine the final product of the given reaction sequence, we will follow each step carefully.

### Step 1: Hydroboration of the Alkene
The starting compound is `(CH3)2=CHCH2CH3`, which is an alkene. When this alkene reacts with `BH3` in `THF`, hydroboration occurs. According to the anti-Markovnikov rule, the boron atom (from `BH3`) will attach to the less substituted carbon, while hydrogen will add to the more substituted carbon.

1. The alkene `(CH3)2=CHCH2CH3` will undergo hydroboration to form a trialkylborane. The structure after this step will be:
- **Intermediate**: `CH3-CH(CH3)-CH2-CH2-BH2`

### Step 2: Oxidation with H2O2 and OH-
Next, the trialkylborane is treated with `H2O2` and `OH-`, which leads to oxidation. The boron atom is replaced with a hydroxyl group (-OH).

2. The product after this oxidation will be:
- **Alcohol**: `CH3-CH(CH3)-CH2-CH2-OH`

### Step 3: Oxidation with PCC
The alcohol formed in the previous step is then oxidized using `PCC` (Pyridinium chlorochromate), which converts the secondary alcohol to a ketone.

3. The resulting ketone will be:
- **Ketone**: `CH3-CH(CH3)-C(=O)-CH2-CH3`

### Step 4: Reaction with Grignard Reagent
Now, the ketone is treated with a Grignard reagent, `CH3MgBr`. The Grignard reagent acts as a nucleophile and attacks the carbonyl carbon of the ketone.

4. The product after this reaction will be:
- **Intermediate**: `CH3-CH(CH3)-C(OH)(CH3)-CH2-CH3`

### Step 5: Hydrolysis
Finally, hydrolysis of the intermediate will yield the final alcohol product.

5. The final product will be:
- **Final Product**: `2,3-dimethylpentan-3-ol`

### Final Answer
The final product of the reaction sequence is **2,3-dimethylpentan-3-ol**.

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