Which of the following reactions will result in the formation of a chiral centre in the product?

Options

A. `CH_(3)CH=CHCH_(3)+Hbrrarr`
B. `CH_(3)CH=CH_(2)+HOBrrarr`
C. `CH_(3)CH_(2)CH=CH_(2)+Hbroverset(H_(2)O_(2))rarr`
D. `CH_(3)CH_(2)CH=CH_(2)+Hbrrarr`

Answer

To determine which of the given reactions will result in the formation of a chiral center in the product, we need to analyze each reaction step by step.

### Step 1: Understanding Chiral Centers
A chiral center (or chiral carbon) is a carbon atom that is attached to four different groups. This asymmetry is what gives rise to chirality, meaning the molecule can exist in two non-superimposable mirror images (enantiomers).

### Step 2: Analyzing Each Reaction
1. **Reaction A**:
- The alkene reacts with HBr.
- According to Markovnikov's rule, the bromine (Br) will attach to the carbon with fewer hydrogens.
- If both carbons have the same number of hydrogens, Br can attach to either carbon.
- In this case, we can see that one of the carbons will end up with four different groups attached (the other carbon will have two hydrogens, one bromine, and one carbon chain).
- **Conclusion**: This reaction will form a chiral center.

2. **Reaction B**:
- The alkene reacts with OH⁻ and Br⁺.
- Again, applying Markovnikov's rule, OH⁻ will go to the carbon with fewer hydrogens.
- The product will have a carbon bonded to OH, Br, one hydrogen, and a carbon chain, resulting in four different groups.
- **Conclusion**: This reaction will also form a chiral center.

3. **Reaction C**:
- The alkene reacts with HBr in the presence of H₂O₂.
- Here, the anti-Markovnikov rule applies, meaning Br⁻ will attach to the carbon with more hydrogens.
- The resulting product will have one carbon bonded to two hydrogens and Br, and the other carbon will have two hydrogens, resulting in no chiral center.
- **Conclusion**: This reaction will not form a chiral center.

4. **Reaction D**:
- The alkene reacts with HBr.
- Following Markovnikov's rule, Br will attach to the carbon with fewer hydrogens.
- The product will have a carbon bonded to Br, one hydrogen, and two different carbon chains, resulting in four different groups.
- **Conclusion**: This reaction will form a chiral center.

### Final Answer
The reactions that will result in the formation of a chiral center are:
- **Option A**
- **Option B**
- **Option D**