`R-CO-O-R' underset("aluminium hydride" -78^(@)C)overset("diisobutyl")rarr Y+R'-OH`
The product Y is

Options

A. `R-CH_(2)-OH`
B. `R-CHO`
C. `R-COOH`
D. `R-CH_(3)`

Answer

To determine the product Y from the reaction of an ester (R-CO-O-R') with diisobutyl aluminium hydride (DIBAL-H) at -78°C, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
The reactant is an ester, represented as R-CO-O-R'. The ester consists of a carbonyl group (C=O) and an alkoxy group (O-R').

2. **Recognize the Reducing Agent**:
The reducing agent used in this reaction is diisobutyl aluminium hydride (DIBAL-H). DIBAL-H is known for its ability to selectively reduce esters to aldehydes.

3. **Understand the Reaction Conditions**:
The reaction is carried out at a low temperature of -78°C. This low temperature is crucial as it helps to control the reaction and prevent further reduction of the aldehyde that is formed.

4. **Predict the Reaction Outcome**:
When an ester is treated with DIBAL-H, it undergoes reduction. The carbonyl carbon of the ester is reduced, leading to the formation of an aldehyde. The alkoxy group (O-R') is released as an alcohol (R'-OH).

5. **Write the Product**:
The product Y formed from the reduction of the ester (R-CO-O-R') is an aldehyde, which can be represented as R-CHO. Therefore, the product Y is R-CHO.

### Final Answer:
The product Y is R-CHO (an aldehyde).

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