The structure of the compound that gives a tribromo derivative on treatment with bromine water is:

Options

A.
B.
C.
D.

Answer

To determine the structure of the compound that gives a tribromo derivative upon treatment with bromine water, we need to analyze the substituents on the aromatic ring and their directing effects on electrophilic substitution reactions.

### Step-by-Step Solution:

1. **Understanding Electrophilic Aromatic Substitution**:
- In electrophilic aromatic substitution, substituents on the benzene ring can either activate or deactivate the ring towards further substitution.
- Activating groups are generally ortho/para-directing, while deactivating groups are usually meta-directing.

2. **Analyzing the Given Options**:
- We will examine each option to see which one can yield a tribromo derivative when treated with bromine water.

3. **Option A**:
- Contains a CH3 group and an OH group.
- Both CH3 and OH are ortho/para-directing. However, the positions available for bromination will not allow for substitution at three different positions due to steric hindrance.
- **Conclusion**: Does not give a tribromo derivative.

4. **Option B**:
- Contains both CH3 and OH groups.
- Both groups are ortho/para-directing, allowing bromination at three different positions (ortho to CH3, ortho to OH, and para to OH).
- **Conclusion**: This compound can give a tribromo derivative.

5. **Option C**:
- Contains an SO3H group and an OH group.
- The OH group is ortho/para-directing, while SO3H is meta-directing. However, the OH group dominates, allowing for bromination at three positions.
- **Conclusion**: This compound can also give a tribromo derivative.

6. **Option D**:
- Contains an OH group and a COOH group.
- The OH group is ortho/para-directing, while COOH is meta-directing. The polar solvent (water) enhances the electron-donating ability of the OH group, allowing for substitution at three positions.
- **Conclusion**: This compound can also give a tribromo derivative.

7. **Final Answer**:
- The structures that give a tribromo derivative on treatment with bromine water are options B, C, and D.