Which of the following compound(s) will give dimethyl glyoxal with Se₀2?

• A. Acetone
• B. Acetophenone
• C. Ethyl methyl ketone
• D. Propionaldehyde

To determine which compound will yield dimethyl glyoxal when reacted with selenium dioxide (SeO2), we need to consider the structure and reactivity of each option. Dimethyl glyoxal is a diketone with the formula C5H8O2, specifically 3,3-dimethyl-2-butanone. The reaction with SeO2 typically involves oxidation processes, particularly of ketones and aldehydes. Let's break down each compound to see which one fits the criteria.

Analyzing Each Compound

• Acetone (A): This is a simple ketone (2-propanone) with the structure CH3COCH3. When oxidized, it can form a diketone, specifically dimethyl glyoxal. The presence of two methyl groups adjacent to the carbonyl makes it a suitable candidate for this reaction.
• Acetophenone (B): This compound has a phenyl group attached to a carbonyl (C6H5COCH3). While it can undergo oxidation, the presence of the aromatic ring may lead to different products rather than forming dimethyl glyoxal directly.
• Ethyl Methyl Ketone (C): Also known as 3-pentanone, this compound has the structure CH3COC2H5. Similar to acetone, it can be oxidized, but the resulting products are not likely to yield dimethyl glyoxal due to the additional ethyl group disrupting the formation of the diketone.
• Propionaldehyde (D): This is an aldehyde (C2H5CHO). Aldehydes can be oxidized to carboxylic acids or ketones, but in this case, it does not have the necessary structure to form dimethyl glyoxal directly.

Identifying the Correct Answer

Based on the analysis, the most suitable compound that can yield dimethyl glyoxal upon oxidation with SeO2 is Acetone (A). The oxidation process will convert acetone into a diketone structure, specifically dimethyl glyoxal, due to the presence of two methyl groups that can be oxidized effectively.

Conclusion

In summary, when considering the reactivity of the given compounds with selenium dioxide, acetone stands out as the only compound that can be transformed into dimethyl glyoxal. The oxidation of acetone leads to the formation of the diketone, making it the correct choice among the options provided.