Cyanohydrin of which of the following compound can forms lactic and

Options

A. `CH_(3)CH_(2)CHO`
B. `CH_(3)CHO`
C. `HCHO`
D. `CH_(3)COCH_(3)`

Answer

To solve the question of which compound can form lactic acid via cyanohydrin formation, we will follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Lactic Acid**:
Lactic acid has the structure CH3-CHOH-COOH. It consists of three carbon atoms, one hydroxyl group (-OH), and one carboxylic acid group (-COOH).

2. **Identify the General Structure of Cyanohydrin**:
The general structure of a cyanohydrin is R-CHOH-CN, where R can be a hydrogen or an alkyl group. The cyanohydrin contains a carbon atom bonded to both a hydroxyl group and a cyanide group.

3. **Determine the Number of Carbons Needed**:
Since lactic acid has three carbon atoms, we need to ensure that the cyanohydrin we choose can provide the necessary carbon atoms to form lactic acid.

4. **Analyze the Given Options**:
- Check each compound option to see how many carbon atoms they provide when forming a cyanohydrin.
- The compound must provide two additional carbon atoms to the one from the cyanohydrin to total three carbons.

5. **Select the Correct Compound**:
- After analyzing the options, identify which compound can yield the required three carbon atoms when reacted with HCN (hydrogen cyanide).
- For example, if one of the options is acetaldehyde (CH3CHO), it has two carbons. When it reacts with HCN, it forms a cyanohydrin (CH3-CHOH-CN) which can then be hydrolyzed to form lactic acid.

6. **Confirm the Reaction**:
- The reaction of the cyanohydrin with water (hydrolysis) will yield the corresponding carboxylic acid (in this case, lactic acid) and regenerate the hydroxyl group.

7. **Final Answer**:
- The correct option that can form lactic acid is the one that provides the necessary carbon atoms when reacted with HCN.

### Conclusion:
The answer to the question is option B, which corresponds to the compound that can yield lactic acid through the cyanohydrin mechanism.