Which one of the following compounds is non - benzenoid ?

Options

A.
B.
C.
D.

Answer

To determine which of the given compounds is non-benzenoid, we need to understand the definitions of benzenoid and non-benzenoid compounds.

### Step-by-Step Solution:

1. **Define Benzenoid and Non-Benzenoid Compounds**:
- **Benzenoid Compounds**: These are compounds that contain at least one benzene ring in their structure. A benzene ring consists of six carbon atoms arranged in a hexagonal ring with alternating double bonds.
- **Non-Benzenoid Compounds**: These are compounds that do not contain any benzene rings in their structure.

2. **Analyze Each Option**:
- **Option 1**: Check if it contains a benzene ring. If it has a benzene structure (six carbon atoms in a cyclic arrangement with alternating double bonds), it is a benzenoid compound.
- **Option 2**: Similarly, check for the presence of one or more benzene rings. If there are two benzene rings, it is still considered a benzenoid compound.
- **Option 3**: Again, check for the presence of three benzene rings. If present, it is a benzenoid compound.
- **Option 4**: Look for any benzene rings. If there are no benzene rings in the structure, it is classified as a non-benzenoid compound.

3. **Identify the Correct Option**:
- After analyzing all options:
- Option 1 has a benzene ring → Benzenoid
- Option 2 has two benzene rings → Benzenoid
- Option 3 has three benzene rings → Benzenoid
- Option 4 has no benzene rings → Non-benzenoid

4. **Conclusion**:
- The correct answer is **Option 4**, as it is the only compound that does not contain any benzene rings, making it a non-benzenoid compound.