Which of the following has maximum laevorotation ?

Options

A. D-Glucose
B. D-Fructose
C. Sucrose
D. Invert sugar

Explanation

To determine which of the given sugars has the maximum laevorotation, we need to analyze the specific rotations of each sugar mentioned in the question: D glucose, D fructose, sucrose, and invert sugar.

### Step-by-Step Solution:

1. **Identify the Specific Rotation of D Glucose**:
- D glucose has a specific rotation of +52.5°.
- This means it rotates plane-polarized light to the right (dextrorotation).

2. **Identify the Specific Rotation of D Fructose**:
- D fructose has a specific rotation of -92.4°.
- This indicates it rotates plane-polarized light to the left (laevorotation).

3. **Identify the Specific Rotation of Sucrose**:
- Sucrose is a disaccharide made up of glucose and fructose. Its specific rotation is not directly given in the transcript, but it is known to be around +66.5°.

4. **Calculate the Specific Rotation of Invert Sugar**:
- Invert sugar is a mixture of glucose and fructose. Its specific rotation can be calculated by adding the specific rotations of D glucose and D fructose:
- Specific rotation of invert sugar = Specific rotation of D glucose + Specific rotation of D fructose
- = +52.5° + (-92.4°) = -39.9°.

5. **Compare the Specific Rotations**:
- D glucose: +52.5°
- D fructose: -92.4°
- Sucrose: +66.5° (approximate)
- Invert sugar: -39.9°

6. **Determine the Maximum Laevorotation**:
- Among the options, D fructose has the most negative value (-92.4°), which indicates it has the maximum laevorotation compared to the others.

### Conclusion:
The sugar with the maximum laevorotation is **D fructose**.

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