The compound that is chiral

Options

A. 3-Methyl-3-hexane
B. 1-Chloro-4-methylcyclohexane
C. 2-Phenylpentane
D. 1,3-Diisopropylbenzene

Answer

To determine which compounds are chiral, we need to identify the presence of chiral carbon atoms in each compound. A chiral carbon atom is one that has four different groups attached to it. Let's analyze the given compounds step by step.

### Step 1: Analyze 3-Methylhexane
1. **Structure**: The structure of 3-methylhexane is CH3-CH2-CH(CH3)-CH2-CH2-CH3.
2. **Identify Carbon Atoms**: Check each carbon atom in the chain.
3. **Chirality Check**:
- Carbon 1 (CH3): Attached to three hydrogens (not chiral).
- Carbon 2 (CH2): Attached to two hydrogens (not chiral).
- Carbon 3 (CH): Attached to one hydrogen, one methyl (CH3), one ethyl (CH2-CH3), and one propyl (CH2-CH2-CH3) group (this is chiral).
- Carbon 4 (CH2): Attached to two hydrogens (not chiral).
- Carbon 5 (CH2): Attached to two hydrogens (not chiral).
- Carbon 6 (CH3): Attached to three hydrogens (not chiral).
4. **Conclusion**: 3-Methylhexane has one chiral carbon atom (Carbon 3), so it is a chiral compound.

### Step 2: Analyze 1-Chloro-4-methylcyclohexane
1. **Structure**: The structure is cyclohexane with a chlorine and a methyl group.
2. **Identify Carbon Atoms**: Check each carbon atom in the cyclohexane ring.
3. **Chirality Check**:
- All carbon atoms in the ring have at least two hydrogens attached (not chiral).
- The carbon with chlorine and methyl has two identical groups (hydrogens) attached (not chiral).
4. **Conclusion**: There are no chiral carbon atoms in 1-chloro-4-methylcyclohexane, so it is not a chiral compound.

### Step 3: Analyze 1-Phenyl-2-methylpropane
1. **Structure**: The structure is CH3-CH(CH3)-CH2-phenyl.
2. **Identify Carbon Atoms**: Check each carbon atom.
3. **Chirality Check**:
- Carbon 1 (CH3): Attached to three hydrogens (not chiral).
- Carbon 2 (CH): Attached to one hydrogen, one methyl (CH3), one phenyl, and one propyl group (this is chiral).
- Carbon 3 (CH2): Attached to two hydrogens (not chiral).
4. **Conclusion**: 1-Phenyl-2-methylpropane has one chiral carbon atom (Carbon 2), so it is a chiral compound.

### Step 4: Analyze 1,3-Diisopropylbenzene
1. **Structure**: The structure is benzene with two isopropyl groups.
2. **Identify Carbon Atoms**: Check each carbon atom in the benzene ring and the isopropyl groups.
3. **Chirality Check**:
- All carbon atoms in the benzene ring are attached to at least two hydrogens (not chiral).
- The carbon atoms in the isopropyl groups have two identical groups (methyls) attached (not chiral).
4. **Conclusion**: There are no chiral carbon atoms in 1,3-diisopropylbenzene, so it is not a chiral compound.

### Final Conclusion
The chiral compounds identified are:
- 3-Methylhexane
- 1-Phenyl-2-methylpropane