Give the structure of the following compounds :
(i) 4-Nitropropiophenone
(ii) 2-Hydroxycyclopentanecarbaldehyde
(iii) Phenyl acetaldehyde.

Explanation

To solve the question, we need to provide the structures of the given compounds step by step.

### Step 1: Structure of 4-Nitropropiophenone
1. **Identify the components**: The name "4-nitropropiophenone" indicates that we have a phenone (ketone) structure with a nitro group at the 4th position and a propyl group.
2. **Draw the phenyl group**: Start by drawing a benzene ring (C6H5).
3. **Add the ketone group**: Attach a carbonyl group (C=O) to the benzene ring. This carbonyl carbon will also be part of the propyl chain.
4. **Add the propyl group**: The propyl group (C3H7) is attached to the carbon of the carbonyl group.
5. **Add the nitro group**: Place the nitro group (NO2) at the 4th position of the benzene ring, counting from the carbon that has the carbonyl group as position 1.
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