How many chiral compounds are possible on mono chlorination of 2-methyl butane ?

Options

A. 2
B. 4
C. 6
D. 8

Explanation

To determine how many chiral compounds are possible from the monochlorination of 2-methylbutane, we can follow these steps:

### Step 1: Understand the Structure of 2-Methylbutane
2-Methylbutane has the following structure:
- It consists of a butane chain with a methyl group attached to the second carbon.
- The structural formula can be represented as:
CH3-CH(CH3)-CH2-CH3

### Step 2: Identify Possible Monochlorination Sites
Monochlorination involves replacing one hydrogen atom with a chlorine atom. We need to identify the hydrogen atoms that can be replaced:
- There are three types of hydrogen atoms in 2-methylbutane:
1. Hydrogens on the terminal CH3 groups (2 CH3 groups)
2. Hydrogens on the second carbon (the one with the methyl group)
3. Hydrogens on the third carbon

### Step 3: Perform Monochlorination
Now we will consider the chlorination at different positions:
1. **Chlorination at the terminal CH3 (1st carbon)**:
- Resulting compound: CH2Cl-CH(CH3)-CH2-CH3 (This carbon is chiral)

2. **Chlorination at the second carbon (the one with the methyl group)**:
- Resulting compound: CH3-CHCl-CH2-CH3 (This carbon is not chiral because it has two identical methyl groups)

3. **Chlorination at the third carbon**:
- Resulting compound: CH3-CH(CH3)-CHCl-CH3 (This carbon is chiral)

4. **Chlorination at the terminal CH3 of the second carbon**:
- Resulting compound: CH3-CH(CH2Cl)-CH2-CH3 (This carbon is chiral)

### Step 4: Identify Chiral Compounds
From the above results, we can identify the chiral centers:
- The first compound (from chlorination of the first carbon) has a chiral center.
- The third compound (from chlorination of the third carbon) also has a chiral center.
- The second compound does not have a chiral center.
- The fourth compound has a chiral center.

### Step 5: Count the Chiral Compounds
After analyzing the products, we find that there are **2 chiral compounds** resulting from the monochlorination of 2-methylbutane.

### Final Answer
Thus, the total number of chiral compounds possible from the monochlorination of 2-methylbutane is **2**.

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