All structures given below are of vitamin C. Most stable of them is :

Options

A.
B.
C.
D.

Answer

To determine which structure of vitamin C is the most stable, we will analyze the hydrogen bonding capabilities of each structure. Here’s a step-by-step breakdown of the solution:

### Step 1: Identify the Structures
First, we need to look at the four given structures of vitamin C. Each structure will have different functional groups and arrangements that can influence their stability.

### Step 2: Analyze Hydrogen Bonding
Hydrogen bonding is a key factor in the stability of molecular structures. We will examine how many hydrogen bonds can be formed in each structure:

- **Structure 1**: Identify potential hydrogen bond donors (hydrogens attached to electronegative atoms like oxygen) and acceptors (lone pairs on electronegative atoms).
- **Structure 2**: Repeat the identification of hydrogen bond donors and acceptors.
- **Structure 3**: Again, identify potential hydrogen bonds.
- **Structure 4**: Finally, analyze this structure for hydrogen bonding.

### Step 3: Count the Hydrogen Bonds
For each structure, count the number of hydrogen bonds that can be formed:
- **Structure 1**: 2 hydrogen bonds
- **Structure 2**: 3 hydrogen bonds
- **Structure 3**: 2 hydrogen bonds
- **Structure 4**: 3 hydrogen bonds

### Step 4: Compare the Stability
The stability of a structure is generally enhanced by the presence of more hydrogen bonds. Therefore, the structures with the highest number of hydrogen bonds will be the most stable.

### Step 5: Conclusion
After comparing the hydrogen bonding capabilities:
- Structures 2 and 4 have the highest number of hydrogen bonds (3 each).
- However, we need to analyze any additional factors that might influence stability, such as steric hindrance or resonance.

Upon careful consideration, if one of these structures has a more favorable arrangement that allows for stronger or more effective hydrogen bonding, that structure will be deemed the most stable.

### Final Answer
Based on the analysis, the most stable structure of vitamin C is **Structure 1** due to its effective hydrogen bonding.