2-Butanone is best converted to propanoic acid by

Options

A. `NaOH, I_(2)//H^(o+)`
B. Tollen's reagent
C. Fehling solution
D. None of these

Answer

To convert 2-butanone to propanoic acid, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Structure of 2-Butanone**:
2-butanone is a ketone with the structure CH3C(=O)CH2CH3. It has a carbonyl group (C=O) located between two alkyl groups.

2. **Understanding the Conversion**:
To convert 2-butanone to propanoic acid (CH3CH2COOH), we need to break down the carbon chain and introduce a carboxylic acid functional group.

3. **Select the Appropriate Reagent**:
The best reagent for this conversion is iodine (I2) in the presence of a base (OH-), specifically sodium hydroxide (NaOH). This reaction is known as the haloform reaction.

4. **Reaction Mechanism**:
- **Step 1**: The base (OH-) attacks the carbonyl carbon of 2-butanone, forming an enolate ion.
- **Step 2**: The enolate ion reacts with iodine to form an iodo compound.
- **Step 3**: Further reaction with the base leads to the cleavage of the carbon chain and the formation of the carboxylate ion (CH3CH2COO-).
- **Step 4**: Finally, acidification (adding H+) converts the carboxylate ion to propanoic acid.

5. **Final Product**:
The final product of this reaction is propanoic acid (CH3CH2COOH).

### Conclusion:
Thus, the best method to convert 2-butanone to propanoic acid is by using iodine (I2) in the presence of sodium hydroxide (NaOH).