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 of 2,3-pentanediol, we can follow these steps:

### Step 1: Identify the Structure of 2,3-Pentanediol
2,3-Pentanediol is a five-carbon alcohol with hydroxyl (OH) groups located on the second and third carbon atoms. The molecular structure can be represented as follows:
- CH3-CH(OH)-CH(OH)-CH2-CH3

### Step 2: Determine Chiral Centers
A chiral center is a carbon atom that is attached to four different groups. In 2,3-pentanediol, we need to identify the carbon atoms that can be chiral centers:
- Carbon 2 (C2) has the following groups: OH, CH3, H, and the rest of the carbon chain (C3).
- Carbon 3 (C3) has the following groups: OH, CH2 (from C4), H, and the rest of the carbon chain (C2).

Both C2 and C3 are chiral centers because they are attached to four different groups.

### Step 3: Count the Number of Chiral Centers
From the analysis, we have identified:
- 2 chiral centers (C2 and C3).

### Step 4: Calculate the Total Number of Stereoisomers
The formula to calculate the number of stereoisomers based on the number of chiral centers (n) is given by:
\[ \text{Number of stereoisomers} = 2^n \]
Where \( n \) is the number of chiral centers.

In our case:
- \( n = 2 \)
- Therefore, the number of stereoisomers is:
\[ 2^2 = 4 \]

### Conclusion
The total number of stereoisomers of 2,3-pentanediol is **4**.

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