Which of the following give the same product on the reduction with DIBAL-H?

Options

A. `CH_3-(CH_2)_9-CN` and `CH_3(CH_2)_9-COOH`
B. `CH_3-(CH_2)_9-CN` and `CH_3(CH_2)_9-COOC_2H_5`
C. `CH_3-(CH_2)_9-COOH` and `CH_3(CH_2)_9-CHO`
D. `CH_3-(CH_2)_9-COOH` and `CH_3(CH_2)_9COOC_2H_5`

Answer

To solve the question of which compounds give the same product upon reduction with DIBAL-H (Diisobutylaluminum hydride), we will analyze the reduction reactions of the given compounds step by step.

### Step-by-Step Solution:

1. **Understanding DIBAL-H**:
DIBAL-H is a reducing agent commonly used to reduce esters and nitriles to aldehydes. It can also reduce carboxylic acids to alcohols under certain conditions.

2. **Identifying the Compounds**:
We need to identify the compounds we are comparing. Let's assume we have the following:
- A nitrile (R-CN)
- An ester (R-COOR')
- A carboxylic acid (R-COOH)

3. **Reduction of Nitrile**:
When a nitrile (R-CN) is reduced by DIBAL-H, it is converted to an aldehyde (R-CHO):
\[ R-CN \xrightarrow{DIBAL-H} R-CHO \]

4. **Reduction of Ester**:
When an ester (R-COOR') is reduced by DIBAL-H, it also converts to an aldehyde (R-CHO):
\[ R-COOR' \xrightarrow{DIBAL-H} R-CHO + R'OH \]
Here, the ester is reduced to an aldehyde and an alcohol.

5. **Reduction of Carboxylic Acid**:
A carboxylic acid (R-COOH) can be reduced by DIBAL-H to an alcohol (R-CH2OH) if excess DIBAL-H is used. However, if limited DIBAL-H is used, it can also convert to an aldehyde:
\[ R-COOH \xrightarrow{DIBAL-H} R-CHO \quad \text{(limited DIBAL-H)} \]
or
\[ R-COOH \xrightarrow{DIBAL-H} R-CH2OH \quad \text{(excess DIBAL-H)} \]

6. **Conclusion**:
From the above reactions, we can conclude that both the nitrile and the ester give the same product (an aldehyde) when reduced with DIBAL-H. Therefore, the compounds that yield the same product upon reduction with DIBAL-H are the nitrile and the ester.

### Final Answer:
The compounds that give the same product on reduction with DIBAL-H are the nitrile and the ester.

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