Which of the following molecules are chiral?

Options

A.
B.
C.
D.

Answer

To determine which of the given molecules are chiral, we need to follow a systematic approach. Here’s a step-by-step solution:

### Step 1: Understand Chirality
Chirality refers to the property of a molecule that makes it non-superimposable on its mirror image. A chiral molecule typically has at least one stereogenic center (often a carbon atom bonded to four different groups).

### Step 2: Analyze Each Molecule
We will examine each of the provided molecules to determine if they possess chirality.

1. **Molecule A**: Check for symmetry and stereogenic centers. If it has a stereogenic center and lacks a plane of symmetry, it is chiral.
2. **Molecule B**: Identify if there is a carbon atom bonded to four different groups. If yes, it is chiral.
3. **Molecule C**: Look for any symmetry elements. If it has a plane of symmetry or is superimposable on its mirror image, it is achiral.
4. **Molecule D**: Similar to the previous steps, check for stereogenic centers and symmetry.

### Step 3: Determine Chirality
- **Molecule A**: If it has a stereogenic center and lacks symmetry, it is chiral.
- **Molecule B**: If it has a stereogenic center, it is chiral.
- **Molecule C**: If it has symmetry (planar or central), it is achiral.
- **Molecule D**: If it has a stereogenic center and lacks symmetry, it is chiral.

### Step 4: Conclusion
Based on the analysis:
- Molecule B and Molecule D are chiral.
- Molecule A and Molecule C are not chiral.

### Final Answer
The chiral molecules among the given options are **B and D**.

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