Which of the following compounds will behave as a reducing sugar in an aqueous KOH solution ?

Options

A.
B.
C.
D.

Answer

To determine which of the given compounds behaves as a reducing sugar in an aqueous KOH solution, we need to understand the characteristics of reducing sugars. Reducing sugars typically contain either an aldehyde group (–CHO), a ketone group (C=O), or a hemiacetal structure.

### Step-by-Step Solution:

1. **Identify the Functional Groups**:
- We need to analyze the compounds provided in the question to identify the presence of aldehyde, ketone, or hemiacetal groups.

2. **Understanding Reducing Sugars**:
- A reducing sugar is one that can donate electrons to another chemical species, which is often facilitated by the presence of an aldehyde or a ketone functional group. Hemiacetals can also act as reducing sugars because they can convert back to aldehydes or ketones.

3. **Examine Each Compound**:
- For each compound, check for the presence of the aforementioned functional groups.
- If a compound has a free aldehyde or ketone group, it can act as a reducing sugar.

4. **Reactions in Aqueous KOH**:
- When a compound is treated with aqueous KOH, any aldehyde or ketone group can undergo reactions that may confirm its reducing nature.
- For example, if a compound has a ketone group, it can potentially form an alpha-hydroxyketone upon reaction with KOH, indicating it is a reducing sugar.

5. **Conclusion**:
- After analyzing the compounds, identify which one contains a functional group that allows it to act as a reducing sugar. The compound that meets this criterion is the answer to the question.