Which of the following reduction methods is not suitable for
preparing an alcohol ?

Options

A. `CH_3COOC_2H_5+NaBH_4to`
B. `CH_3COOC_2H_5+Na//EtOHto`
C. `CH_3CH_2COCl+LiAlH_4to`
D. `CH_3COOH+H_2overset(Ni)to`

Explanation

To determine which reduction method is not suitable for preparing an alcohol, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Identify the first reaction:**
- The first reaction is between an ester (CH3COOC2H5) and sodium borohydride (NaBH4).
- **Analysis:** NaBH4 is known to reduce aldehydes and ketones but does not effectively reduce esters. Therefore, no alcohol will be formed from this reaction.

2. **Identify the second reaction:**
- The second reaction involves the same ester (CH3COOC2H5) and ethanol (C2H5OH) with nascent hydrogen.
- **Analysis:** This reaction can lead to the formation of an alcohol. Ethanol can provide the necessary conditions for reduction, and thus this method is suitable for preparing an alcohol.

3. **Identify the third reaction:**
- The third reaction is between an acid chloride (RCOCl) and lithium aluminium hydride (LiAlH4).
- **Analysis:** LiAlH4 is a strong reducing agent that can reduce acid chlorides to primary alcohols. Therefore, this method is suitable for preparing an alcohol.

4. **Identify the fourth reaction:**
- The fourth reaction involves a carboxylic acid (CH3COOH) reacting with hydrogen (H2) in the presence of nickel.
- **Analysis:** This reaction can reduce carboxylic acids to primary alcohols. Therefore, this method is also suitable for preparing an alcohol.

### Conclusion:
Based on the analysis of each reaction, the reduction method that is **not suitable** for preparing an alcohol is the first option: **CH3COOC2H5 + NaBH4**.

### Final Answer:
**The reduction method that is not suitable for preparing an alcohol is: CH3COOC2H5 + NaBH4.**

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