Which of the following is an anhydride ?

Options

A.
B.
C.
D.

Explanation

To determine which of the given options is an anhydride, we need to understand what an anhydride is. An anhydride is a compound that can be derived from an acid by the removal of water (H2O). In organic chemistry, anhydrides typically contain the anhydride functional group, which consists of two carbonyl (C=O) groups connected by an oxygen atom (O). The general structure of an anhydride can be represented as RCO-O-COR', where R and R' can be hydrogen or hydrocarbon groups.

### Step-by-Step Solution:

1. **Identify the Anhydride Structure**:
- An anhydride has the structure RCO-O-COR', which means it contains two carbonyl groups (C=O) linked by an oxygen atom (O).

2. **Examine Each Option**:
- Look at each option provided in the question and check if they contain the anhydride structure.
- For example, if one of the options has the structure C=O-O-C=O, it would qualify as an anhydride.

3. **Determine the Correct Option**:
- After analyzing all the options, identify which one contains the anhydride structure.
- If only one option has the anhydride structure, that option is the correct answer.

4. **Conclude**:
- Based on the analysis, select the option that is an anhydride.

### Conclusion:
- The answer is the option that contains the anhydride structure, which we identified as option E.