Which can show geometrical isomer ?

Options

A.
B.
C.
D.

Answer

To determine which of the given compounds can show geometrical isomerism, we need to analyze each compound based on the criteria for geometrical isomerism. Geometrical isomerism typically occurs in compounds with a double bond (C=C) where the substituents attached to the carbon atoms of the double bond are different.

### Step-by-Step Solution:

1. **Identify the Compounds**: We have four compounds to consider. Let's denote them as Compound 1, Compound 2, Compound 3, and Compound 4.

2. **Understand the Criteria for Geometrical Isomerism**:
- A compound must have a carbon-carbon double bond (C=C).
- The two carbon atoms involved in the double bond must have two different substituents each.
- The substituents on each carbon should not be identical.

3. **Analyze Compound 1**:
- Compound 1 has a double bond with the following substituents: two hydrogens and a carbon chain.
- Since two of the substituents (hydrogens) are the same, this compound does not meet the criteria for geometrical isomerism.
- **Conclusion**: Compound 1 does not show geometrical isomerism.

4. **Analyze Compound 2**:
- Compound 2 has a double bond with one methyl group (CH3) and one hydrogen attached to one carbon, and an isopropyl group (C3H7) on the other carbon.
- Here, the substituents are different: one is a methyl group and the other is an isopropyl group.
- **Conclusion**: Compound 2 can show geometrical isomerism (it is 4-methylpent-2-ene).

5. **Analyze Compound 3**:
- Compound 3 has a double bond with two hydrogens on one carbon and two different groups on the other carbon.
- However, since both substituents on one carbon are hydrogens, they are identical.
- **Conclusion**: Compound 3 does not show geometrical isomerism.

6. **Analyze Compound 4**:
- Compound 4 has a double bond with two identical substituents (hydrogens) on one of the carbons.
- Since the substituents are the same, it does not meet the criteria for geometrical isomerism.
- **Conclusion**: Compound 4 does not show geometrical isomerism.

7. **Final Conclusion**:
- Among the four compounds analyzed, only Compound 2 (4-methylpent-2-ene) can show geometrical isomerism.

### Final Answer:
The compound that can show geometrical isomerism is **Compound 2 (4-methylpent-2-ene)**.