With oxalic acid, glycerol at `260^(@)`C gives:

Options

A. Allyl alcohol
B. Glyceryl mono-oxalate
C. Formic acid
D. Glyceraldehyde

Answer

To solve the question regarding the reaction of glycerol with oxalic acid at 260°C, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactants in this reaction are glycerol (C3H8O3) and oxalic acid (C2H2O4).

2. **Understand the Reaction Conditions**:
- The reaction takes place at a high temperature of 260°C, which is significant for driving dehydration and decarboxylation reactions.

3. **Dehydration Process**:
- When glycerol is heated with oxalic acid, two water molecules are removed. This dehydration step leads to the formation of an intermediate compound known as glycerol dioxalate.

\[ \text{Glycerol} \rightarrow \text{Glycerol dioxalate} + 2 \text{H}_2\text{O} \]

4. **Formation of Glycerol Dioxalate**:
- The structure of glycerol dioxalate can be represented as:
\[ \text{CH}_2\text{OOC}-\text{CHOOC}-\text{CH}_2\text{OH} \]

5. **Decarboxylation Process**:
- Upon further heating, the glycerol dioxalate undergoes decarboxylation, where two carbon dioxide (CO2) molecules are released.

\[ \text{Glycerol dioxalate} \rightarrow \text{Allyl alcohol} + 2 \text{CO}_2 \]

6. **Final Product Formation**:
- The final product formed from this reaction is allyl alcohol (C3H6O), which has the structure:
\[ \text{CH}_2=CH-\text{CH}_2\text{OH} \]

7. **Conclusion**:
- Therefore, the product formed when glycerol reacts with oxalic acid at 260°C is allyl alcohol.

### Final Answer:
The correct answer is **allyl alcohol**.

---