Cannizaro's reaction is not given by

Options

A.
B.
C. HCHO
D. `CH_(3)CHO`

Explanation

To determine which compound does not undergo Cannizzaro's reaction, we first need to understand the conditions under which Cannizzaro's reaction occurs and the characteristics of the compounds involved.

### Step-by-Step Solution:

1. **Understanding Cannizzaro's Reaction**:
- Cannizzaro's reaction is a redox reaction that occurs in aldehydes lacking alpha hydrogen atoms when treated with a strong base (like NaOH or KOH). In this reaction, one molecule of the aldehyde is oxidized to a carboxylic acid, while another molecule is reduced to an alcohol.

2. **Identifying the Role of Alpha Hydrogen**:
- Compounds that have alpha hydrogen atoms (hydrogens attached to the carbon adjacent to the carbonyl group) can undergo aldol condensation instead of Cannizzaro's reaction. Aldol condensation involves the formation of a β-hydroxy aldehyde or ketone, which can further dehydrate to form an α,β-unsaturated carbonyl compound.

3. **Analyzing the Given Compounds**:
- To answer the question, we need to analyze the compounds provided (not specified in the question but typically include formaldehyde, acetaldehyde, etc.) and check for the presence of alpha hydrogen.
- **Formaldehyde (HCHO)**: No alpha hydrogen; can undergo Cannizzaro's reaction.
- **Acetaldehyde (CH3CHO)**: Has alpha hydrogen; cannot undergo Cannizzaro's reaction.
- Other aldehydes or ketones can be analyzed similarly.

4. **Conclusion**:
- The compound that does not undergo Cannizzaro's reaction is the one that has alpha hydrogen. Therefore, if we consider common examples, acetaldehyde (or any aldehyde with alpha hydrogen) will not undergo Cannizzaro's reaction.

### Final Answer:
The compound that does not undergo Cannizzaro's reaction is the one that has alpha hydrogen, such as acetaldehyde (CH3CHO).

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