Monochlorination of (S)-2-chlorobutane can give:

Options

A. (S)-1,2-dichlorobutance
B. `(R)-1,2-"dichlorobutane"`
C. (2R,3S)-2,3-dichlorobutane
D. (2R,3R)-2,3-dichlorobutane

Explanation

To solve the question regarding the monochlorination of (S)-2-chlorobutane, we will follow these steps:

### Step 1: Understand the Structure of (S)-2-Chlorobutane
(S)-2-chlorobutane is a chiral molecule with the following structure:
- It has a chlorine atom (Cl) attached to the second carbon of a four-carbon chain (butane).
- The configuration is (S), meaning that the highest priority substituent (Cl) is on the left when the molecule is oriented correctly.

### Step 2: Identify Possible Monochlorination Sites
When monochlorination occurs, a chlorine atom can replace a hydrogen atom on any of the available carbon atoms. In (S)-2-chlorobutane, the potential sites for chlorination are:
- The first carbon (C1)
- The second carbon (C2) - already has a Cl, so this is not a site for further chlorination
- The third carbon (C3)
- The fourth carbon (C4)

### Step 3: Draw Possible Products
1. **Chlorination at C1**:
- This will yield 1,2-dichlorobutane.
- Configuration: (S)-2-chlorobutane remains unchanged at C2, and C1 gets a Cl.

2. **Chlorination at C3**:
- This will yield 2,3-dichlorobutane.
- Configuration: The molecule will have Cl at C2 and C3. This can lead to two stereoisomers: (2R,3S)-2,3-dichlorobutane and (2S,3R)-2,3-dichlorobutane.

3. **Chlorination at C4**:
- This will yield 2,4-dichlorobutane.
- Configuration: The molecule will have Cl at C2 and C4, which does not create a new chiral center.

### Step 4: Identify Stereoisomers
From the chlorination at C3, we have two stereoisomers:
- (2R,3S)-2,3-dichlorobutane
- (2S,3R)-2,3-dichlorobutane

### Step 5: List All Possible Products
The final products from the monochlorination of (S)-2-chlorobutane are:
1. 1,2-dichlorobutane
2. (2R,3S)-2,3-dichlorobutane
3. (2S,3R)-2,3-dichlorobutane
4. 2,4-dichlorobutane

### Conclusion
Thus, the monochlorination of (S)-2-chlorobutane can yield the following compounds:
- 1,2-dichlorobutane
- (2R,3S)-2,3-dichlorobutane
- (2S,3R)-2,3-dichlorobutane
- 2,4-dichlorobutane