Ethyl acetoacetate shows, which type of isomerism

Options

A. Chain
B. Optical
C. Metamerism
D. Tautomerism

Explanation

To determine the type of isomerism exhibited by ethyl acetoacetate, we need to analyze its structure and behavior.

### Step-by-Step Solution:

1. **Identify the Structure**: Ethyl acetoacetate is an ester with the molecular formula C₅H₈O₄. Its structure can be represented as:
\[ \text{CH}_3\text{C(=O)CH}_2\text{COOC}_2\text{H}_5 \]
This shows that it has both a carbonyl (keto) and an ester functional group.

2. **Consider Possible Isomerisms**: Isomerism can be classified into several types, including structural isomerism and stereoisomerism. Ethyl acetoacetate can exhibit tautomerism due to the presence of a keto and enol form.

3. **Tautomerism**: Tautomerism is a specific type of structural isomerism where two isomers (tautomers) can interconvert. In the case of ethyl acetoacetate, it can exist in a keto form (with a carbonyl group) and an enol form (with a hydroxyl group adjacent to a double bond). The keto form is more stable, but under certain conditions, it can tautomerize to the enol form.

4. **Conclusion**: Therefore, ethyl acetoacetate primarily exhibits tautomerism, which is a type of structural isomerism.

### Final Answer:
Ethyl acetoacetate shows tautomerism.