Which of the following rection given secondary alcohol?

Options

A. `CH_(3)-MgBr+HCHOoverset(Aq.NH_(4)Cl)to`
B. `CH_(3)-MgBr+CH_(3)-CHOoverset(Aq. NH_(4)Cl)to`
C. `Ph-MgBr+Ph-CHOoverset(Aq. NH_(4)Cl)to`
D. `Ph-MgBr+CH_(3)-CO-CH_(3)overset(Aq. NH_(4)Cl)to`

Explanation

To determine which reaction produces a secondary alcohol, we need to analyze each of the given reactions step by step.

### Step-by-Step Solution:

1. **Identify the Reactions**: We need to look at each reaction provided and identify the reactants involved. The key reactants are typically aldehydes or ketones when reacting with Grignard reagents.

2. **First Reaction**:
- **Reactants**: Formaldehyde (HCHO) + Grignard reagent (e.g., CH3MgBr).
- **Product**: When formaldehyde reacts with a Grignard reagent, it forms a primary alcohol (ethanol, CH3CH2OH).
- **Conclusion**: This reaction produces a primary alcohol, so it is incorrect for producing a secondary alcohol.

3. **Second Reaction**:
- **Reactants**: Acetaldehyde (CH3CHO) + Grignard reagent (e.g., CH3MgBr).
- **Product**: The reaction of acetaldehyde with a Grignard reagent leads to the formation of a secondary alcohol (propan-2-ol, CH3CHOHCH3).
- **Conclusion**: This reaction produces a secondary alcohol, so it is correct.

4. **Third Reaction**:
- **Reactants**: Benzaldehyde (C6H5CHO) + Grignard reagent.
- **Product**: The product of this reaction will be a benzyl alcohol (C6H5CH2OH), which is a primary alcohol.
- **Conclusion**: This reaction produces a primary alcohol, so it is incorrect for producing a secondary alcohol.

5. **Fourth Reaction**:
- **Reactants**: Acetone (CH3COCH3) + Grignard reagent.
- **Product**: The reaction of acetone with a Grignard reagent leads to the formation of a tertiary alcohol (e.g., tert-butanol).
- **Conclusion**: This reaction produces a tertiary alcohol, so it is incorrect for producing a secondary alcohol.

### Final Answer:
The reaction that gives a secondary alcohol is the **second reaction** involving acetaldehyde and a Grignard reagent.

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