The meso form of 2,3 4- pentanetriol is :

Options

A.
B.
C.
D. Both (b) and ( c)

Answer

To determine the meso form of 2,3,4-pentanetriol, we need to analyze the structure of the compound and identify if it has any planes of symmetry or centers of symmetry. Here’s a step-by-step solution:

### Step 1: Understand the Structure of 2,3,4-Pentanetriol
2,3,4-Pentanetriol is a five-carbon chain (pentane) with three hydroxyl (OH) groups attached to the second, third, and fourth carbon atoms.

### Step 2: Draw the Structure
The structure can be represented as follows:
```
CH3-CHOH-CHOH-CHOH-CH3
```
Where the hydroxyl groups are on the 2nd, 3rd, and 4th carbon atoms.

### Step 3: Identify Chiral Centers
In the structure, we need to identify the chiral centers. A chiral center is typically a carbon atom that is attached to four different groups. In 2,3,4-pentanetriol:
- The 2nd carbon (C-2) is attached to -OH, -H, -C3H7, and -C1H3 (not chiral).
- The 3rd carbon (C-3) is attached to -OH, -H, -C2H5, and -C4H9 (chiral).
- The 4th carbon (C-4) is attached to -OH, -H, -C3H7, and -C5H11 (chiral).

### Step 4: Check for Symmetry
To determine if the compound is meso, we need to check for a plane of symmetry:
- If we draw the molecule, we can see that there is a plane of symmetry between the two halves of the molecule. The left side (C-2 and C-3) mirrors the right side (C-4 and C-5).

### Step 5: Conclusion
Since 2,3,4-pentanetriol has a plane of symmetry, it is classified as a meso compound. The meso form does not exhibit optical activity due to the internal compensation of chirality.

### Final Answer
The meso form of 2,3,4-pentanetriol is the compound with a plane of symmetry, which can be represented in its structural formula.