`alpha`-D-Glucopyranose and `beta`-D-Glucopyranose are

Options

A. Anomers
B. Epimers
C. Diastereomers
D. Enantiomers

Answer

To determine the relationship between alpha-D-glucopyranose and beta-D-glucopyranose, we can follow these steps:

### Step 1: Understand the Structures
First, we need to understand the structures of alpha-D-glucopyranose and beta-D-glucopyranose. Both of these are cyclic forms of glucose.

### Step 2: Draw the Structures
- **Alpha-D-Glucopyranose**: In this structure, the hydroxyl group (-OH) on the anomeric carbon (C1) is positioned below the plane of the ring.
- **Beta-D-Glucopyranose**: In this structure, the hydroxyl group (-OH) on the anomeric carbon (C1) is positioned above the plane of the ring.

### Step 3: Identify the Anomeric Carbon
The anomeric carbon is the carbon that was the carbonyl carbon (C1) in the open-chain form of glucose. The difference between alpha and beta forms is based on the orientation of the hydroxyl group at this carbon.

### Step 4: Compare the Structures
By comparing the two structures:
- In alpha-D-glucopyranose, the -OH group on C1 is down (axial position).
- In beta-D-glucopyranose, the -OH group on C1 is up (equatorial position).

### Step 5: Classify the Relationship
Since alpha-D-glucopyranose and beta-D-glucopyranose differ only in the configuration at the anomeric carbon (C1), they are classified as **anomers**.

### Final Answer
Thus, alpha-D-glucopyranose and beta-D-glucopyranose are **anomers**.

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