Which of the following combinations give t-butyl alcohol when treated with Grignard reagent-

Options

A. `CH_(3)`MgBr + `CH_(3)COCH_(3)`
B. `C_(2)H_(5)`MgBr + `CH_(3)COOH_(3)`
C. `CH_(3)`MgBr + `(CH_(3))_(3)`C. OH
D. `CH_(3)`MgBr + `CH_(3)CH_(2)` CHO

Answer

To determine which combinations give t-butyl alcohol when treated with a Grignard reagent, we will analyze the options step by step.

### Step-by-Step Solution:

1. **Identify the Grignard Reagent**:
The Grignard reagent given in the problem is CH3MgBr (methyl magnesium bromide). This reagent acts as a nucleophile.

2. **Consider the First Option**:
The first option is acetone (CH3C(=O)CH3). When acetone reacts with CH3MgBr, the nucleophilic methyl group (CH3-) will attack the carbonyl carbon of acetone.

- **Reaction**:
\[ CH3C(=O)CH3 + CH3MgBr \rightarrow CH3C(OH)(CH3)CH3 \]
- After hydrolysis, the product formed is t-butyl alcohol (tert-butyl alcohol).

3. **Consider the Second Option**:
The second option is ethyl alcohol (C2H5OH). When ethyl alcohol reacts with CH3MgBr, the ethyl group (C2H5-) will not lead to the formation of t-butyl alcohol.

- **Reaction**:
\[ C2H5OH + CH3MgBr \rightarrow C2H5O- + CH4 \]
- This does not yield t-butyl alcohol.

4. **Consider the Third Option**:
The third option is t-butyl alcohol itself (C(CH3)3OH). When t-butyl alcohol reacts with CH3MgBr, it will not produce any new product as it is already t-butyl alcohol.

- **Reaction**:
\[ C(CH3)3OH + CH3MgBr \rightarrow \text{No new product} \]
- Thus, this option does not yield t-butyl alcohol through a reaction.

5. **Consider the Fourth Option**:
The fourth option is propanal (CH3CH2CHO). When propanal reacts with CH3MgBr, the methyl group will attack the carbonyl carbon.

- **Reaction**:
\[ CH3CH2CHO + CH3MgBr \rightarrow CH3CH2C(OH)(CH3)CH3 \]
- This results in butan-2-ol, not t-butyl alcohol.

### Conclusion:
The only combination that yields t-butyl alcohol when treated with the Grignard reagent CH3MgBr is the first option (acetone).

### Final Answer:
**The correct option is the first one (acetone).**

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