Which of the following reagents can be used to convert
but`-1-y n e` to butanone ?

Options

A. `K_(2)Cr_(2)O_(7)//H^(+)`
B. dil.`H_(2)SO_(4)//HgSO_(4)`
C. `CrO_(3)` in presence of `(CH_(3)CO)_(2)O`
D. `O_(3)//Zn-H_(2)O`

Explanation

To convert but-1-yne to butanone, we need to analyze the reagents provided and their reactions with but-1-yne. Let's go through each reagent step by step.

### Step-by-Step Solution:

1. **Identify the structure of but-1-yne**:
- But-1-yne has the structure CH3CH2C≡CH. It is an alkyne with a triple bond between the second and third carbon atoms.

2. **Consider the first reagent: K2Cr2O7 in the presence of H+**:
- K2Cr2O7 is a strong oxidizing agent. When it reacts with alkynes, it tends to oxidize them to carboxylic acids rather than ketones. Therefore, this reagent will not yield butanone from but-1-yne.
- **Conclusion**: This reagent is **not suitable** for the conversion.

3. **Consider the second reagent: Dilute H2SO4 with HgSO4**:
- The reaction of but-1-yne with dilute H2SO4 in the presence of HgSO4 leads to the hydration of the alkyne. This results in the formation of an enol (CH3CH2C(OH)=CH2), which then tautomerizes to form butanone (CH3CH2C(=O)CH3).
- **Conclusion**: This reagent **can convert but-1-yne to butanone**.

4. **Consider the third reagent: CrO3 in the presence of acetic anhydride (CH3CO2O)**:
- CrO3 is a moderate oxidizing agent and will oxidize but-1-yne to an aldehyde rather than a ketone. Therefore, it will not lead to the formation of butanone.
- **Conclusion**: This reagent is **not suitable** for the conversion.

5. **Consider the fourth reagent: Reductive ozonolysis (O3 followed by Zn/H2O)**:
- Reductive ozonolysis will cleave the alkyne and can lead to the formation of various products, including aldehydes and ketones. However, it does not specifically yield butanone from but-1-yne.
- **Conclusion**: This reagent is **not suitable** for the conversion.

### Final Answer:
The reagent that can be used to convert but-1-yne to butanone is **dilute H2SO4 with HgSO4**.

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