Question

Which of the following is the correct structure of L- Glucose

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is B

To determine the correct structure of L-Glucose, we need to understand its configuration compared to D-Glucose. L-Glucose is the enantiomer of D-Glucose, meaning it is a mirror image of D-Glucose. The main aspect that differentiates them is the configuration around each chiral carbon atom.

In D-Glucose, the hydroxyl group (-OH) on the chiral carbon farthest from the carbonyl group is on the right side in a Fischer projection. In contrast, in L-Glucose, this hydroxyl group is on the left side. L-Glucose can be visualized as a vertical reflection of D-Glucose in a Fischer projection.

Here's a step-by-step explanation of the structural determination:

1. Identify the position of the hydroxyl groups in the L-configuration, opposite of the D-configuration (for all chiral centers).
2. Verify that the structure shown has the terminal hydroxyl group on the left, which indicates its L configuration.
3. Ensure that the configuration of the rest of the molecule aligns with the mirror image property for each chiral center compared to D-Glucose.

Hence, the correct structure of L-Glucose has the hydroxyl group on the left at the chiral carbon farthest from the aldehyde carbon.

The correct structure of L-Glucose as per the provided options is shown in the image below:

This corresponds with the correct structure of L-Glucose, making this the correct answer.