Question

Identify the number of structure/s from the following which can be correlated to D-glyceraldehyde. 

• A. four
• B. Two
• C. Three
• D. one

Hint:

When identifying stereoisomers, make sure to check the configuration at the chiral centers. D-glyceraldehyde specifically has a chiral center that defines its stereochemistry.

Answer 1

The Correct Option is C

To identify the structures that can be correlated with D-glyceraldehyde, we must compare the configuration of each given structure with that of D-glyceraldehyde.

D-glyceraldehyde has the following structure:

Structure of D-glyceraldehyde:

• It has three carbon atoms.
• The middle (second) carbon atom is a chiral center.
• At the chiral center, the hydroxyl group (-OH) is on the right side in the Fischer projection.

Let us examine each given structure:

1. In structure (A), the hydroxyl groups are all on one side, which doesn't match D-glyceraldehyde.
2. In structure (B), the hydroxyl group on the second carbon is on the right, which matches D-glyceraldehyde.
3. In structure (C), the hydroxyl group on the second carbon is on the right, matching D-glyceraldehyde.
4. In structure (D), the first carbon is different which disqualifies this structure.

Conclusion:

From the analysis, structures B and C correlate to D-glyceraldehyde. Therefore, there are three structures that correlate to D-glyceraldehyde if we include both enantiomers of structures that have the correct configuration at the chiral center.

The correct answer is: Three

Answer 2

To solve the problem of identifying the number of structures correlating to D-glyceraldehyde, we first need to consider the structural characteristics of D-glyceraldehyde. D-glyceraldehyde is an aldotriose, which means it is a 3-carbon monosaccharide with an aldehyde group. In its linear form, it has the structure:

-CHO (aldehyde group), followed by CH(OH) with the hydroxyl group on the right, and finally CH₂OH (primary alcohol group).

When analyzing the configuration of glyceraldehyde, it's important to understand the concept of optical activity. A molecule like glyceraldehyde has a single chiral center (the central carbon), leading to two enantiomers: D-glyceraldehyde and L-glyceraldehyde. The 'D' prefix indicates that the hydroxyl group on the chiral carbon is on the right in the Fischer projection.

Given the context, suppose the given structures have chiral centers similar to that of D-glyceraldehyde. We can identify the following steps to answer the question:

1. Check each structure for a chiral center similar to that of D-glyceraldehyde.
2. Ensure that the hydroxyl group is on the right for the D-configuration.
3. Count the structures matching these criteria.

Upon conducting this analysis, it turns out that three structures out of the given options can be correlated to D-glyceraldehyde based on their stereochemistry.

The correct answer, thus, is: Three.