The best reagent to convert pent-3-en-2-ol into pent-3-en-2-one is

Options

A. acidic permanganate
B. acidic dichromate
C. chromic anhydride in glacial acetic acid
D. pyridinium chlorochromate.

Explanation

To convert pent-3-en-2-ol into pent-3-en-2-one, we need to perform an oxidation reaction that specifically targets the alcohol functional group without affecting the alkene. Here’s a step-by-step solution:

### Step 1: Identify the structures
- **Pent-3-en-2-ol**: This compound has a hydroxyl (-OH) group at the second carbon and a double bond between the third and fourth carbons.
- **Pent-3-en-2-one**: This compound has a carbonyl (C=O) group at the second carbon and retains the double bond.

### Step 2: Determine the reaction type
- We need to oxidize the alcohol (-OH) group to a ketone (C=O). This is an oxidation reaction.

### Step 3: Select the appropriate reagent
- The reagent must selectively oxidize the alcohol to a ketone without affecting the alkene.
- A suitable reagent for this transformation is **chromic anhydride (CrO3)** in **glacial acetic acid**. This reagent is known for its ability to oxidize alcohols to ketones.

### Step 4: Write the reaction
- The reaction can be represented as follows:
\[ \text{Pent-3-en-2-ol} + \text{CrO}_3 \text{ (in glacial acetic acid)} \rightarrow \text{Pent-3-en-2-one} \]

### Conclusion
- Therefore, the best reagent to convert pent-3-en-2-ol into pent-3-en-2-one is **chromic anhydride in glacial acetic acid**.