Which one of the following compound will not show enolisation ?

Options

A.
B.
C.
D.

Answer

To determine which compound will not show enolization, we need to analyze the presence of alpha hydrogens in each compound. Enolization occurs when there is a hydrogen atom attached to the carbon adjacent to a carbonyl group (the alpha position).

### Step-by-Step Solution:

1. **Identify the Compounds**: We have four compounds to analyze. Let's denote them as Compound A, Compound B, Compound C, and Compound D.

2. **Check for Alpha Hydrogens**:
- **Compound A**:
- Structure: A cyclic compound with a carbonyl group and a methyl (Me) group.
- Analysis: The carbonyl carbon has one alpha hydrogen. Therefore, it can undergo enolization.

- **Compound B**:
- Structure: A compound with a carbonyl group but no alpha hydrogen.
- Analysis: There are no hydrogen atoms on the carbon adjacent to the carbonyl carbon. Thus, it cannot undergo enolization.

- **Compound C**:
- Structure: Another compound with a carbonyl group.
- Analysis: This compound also lacks alpha hydrogens as all valencies of the adjacent carbon are satisfied. Therefore, it cannot undergo enolization.

- **Compound D**:
- Structure: Similar to Compound B, it has a carbonyl group.
- Analysis: There are no alpha hydrogens present. Hence, it cannot undergo enolization.

3. **Conclusion**:
- Based on the analysis, Compounds B, C, and D do not show enolization due to the absence of alpha hydrogens. Compound A can show enolization but is destabilized due to non-planar geometry. However, the question asks for compounds that do not show enolization, which applies to B, C, and D.

### Final Answer:
All compounds B, C, and D do not show enolization due to the absence of alpha hydrogens.

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