The total number of stereoisomers of 2, 3-pentanediol are

Options

A. four
B. two
C. six
D. three

Answer

To determine the total number of stereoisomers for 2,3-pentanediol, we can follow these steps:

### Step 1: Identify the Structure
2,3-pentanediol has the following structure:
- It is a five-carbon chain (pentane) with hydroxyl (–OH) groups on the second and third carbons.

### Step 2: Determine the Stereocenters
A stereocenter (or chiral center) is a carbon atom that is bonded to four different groups. In 2,3-pentanediol:
- The second carbon (C-2) is attached to:
- A hydroxyl group (–OH)
- A hydrogen atom (–H)
- A carbon chain (C-1)
- A carbon chain (C-3)

- The third carbon (C-3) is attached to:
- A hydroxyl group (–OH)
- A hydrogen atom (–H)
- A carbon chain (C-2)
- A carbon chain (C-4)

Both C-2 and C-3 are stereocenters because they are each bonded to four different groups.

### Step 3: Calculate the Number of Stereoisomers
The formula to calculate the number of stereoisomers is:
\[ \text{Number of stereoisomers} = 2^n \]
where \( n \) is the number of stereocenters.

In this case, we have:
- \( n = 2 \) (since there are two stereocenters)

Thus, the number of stereoisomers is:
\[ 2^2 = 4 \]

### Step 4: Conclusion
The total number of stereoisomers for 2,3-pentanediol is 4.