Which of the following exhibit mutarotation?

Options

A. Glucose
B. Maltose
C. Frctose
D. Galactose

Explanation

To determine which of the given compounds exhibit mutarotation, we need to understand the concept of mutarotation and the structural characteristics that allow for this phenomenon.

### Step-by-Step Solution:

1. **Define Mutarotation**:
- Mutarotation is the change in the optical rotation of a solution as it equilibrates between different anomeric forms of a sugar. This process occurs when a sugar with a hemiacetal group interconverts between its α and β anomers.

2. **Identify Hemiacetal Linkage**:
- A compound must have a hemiacetal linkage to exhibit mutarotation. This linkage is typically found in sugars that can form cyclic structures.

3. **Check for Six-Membered Rings**:
- Mutarotation is commonly observed in sugars that can form six-membered rings (pyranoses).

4. **Look for Multiple Hydroxyl Groups**:
- The presence of multiple hydroxyl (-OH) groups is also necessary for a compound to exhibit mutarotation.

5. **Analyze the Given Compounds**:
- **Glucose**:
- Glucose can exist in a cyclic form (pyranose) and has multiple hydroxyl groups. It exhibits mutarotation.
- **Maltose**:
- Maltose is a disaccharide composed of two glucose units. It also has a hemiacetal linkage and multiple hydroxyl groups, thus it exhibits mutarotation.
- **Fructose**:
- Fructose can exist in a five-membered ring (furanose) but also has a pyranose form. It has multiple hydroxyl groups and exhibits mutarotation.
- **Galactose**:
- Galactose is similar to glucose, can form a six-membered ring, and has multiple hydroxyl groups, thus it exhibits mutarotation.

6. **Conclusion**:
- Since all four compounds (glucose, maltose, fructose, and galactose) have hemiacetal linkages, can form six-membered rings, and contain multiple hydroxyl groups, they all exhibit mutarotation.

### Final Answer:
All of the compounds (1. Glucose, 2. Maltose, 3. Fructose, 4. Galactose) exhibit mutarotation.

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