Which of the following will not show mutarotation?

Options

A. Maltose
B. Lactose
C. Glucose
D. Sucrose

Explanation

To determine which of the following sugars will not show mutarotation, we need to understand the concept of mutarotation and the structural characteristics of the given sugars: maltose, lactose, glucose, and sucrose.

### Step-by-Step Solution:

1. **Understanding Mutarotation**:
- Mutarotation is the change in the optical rotation of a sugar solution as it reaches equilibrium between its anomers (alpha and beta forms). This phenomenon occurs due to the interconversion of these anomers in solution.

2. **Identifying Anomers**:
- Anomers are specific types of stereoisomers that differ at the anomeric carbon (the carbon that was the carbonyl carbon in the open-chain form). For a sugar to show mutarotation, it must have an anomeric carbon that can exist in both alpha and beta forms.

3. **Analyzing the Sugars**:
- **Glucose**:
- Glucose is a monosaccharide with a free aldehyde group. It can exist in both alpha and beta forms, thus it shows mutarotation.
- **Lactose**:
- Lactose is a disaccharide composed of glucose and galactose. It also has a free aldehyde group and can show mutarotation.
- **Maltose**:
- Maltose is another disaccharide made up of two glucose units. It has a free aldehyde group and can show mutarotation.
- **Sucrose**:
- Sucrose is a disaccharide composed of glucose and fructose. In sucrose, the anomeric carbon of both glucose and fructose is involved in the glycosidic bond, which means there is no free aldehyde or ketone group available for mutarotation.

4. **Conclusion**:
- Since sucrose does not have a free aldehyde or ketone group, it cannot form anomers and therefore will not show mutarotation. The correct answer is **sucrose**.

### Final Answer:
**Sucrose will not show mutarotation.**