Which of the following dienes is chiral?

Options

A. `CH_(3)-CH=C=CH_(2)`
B. `CH_(3)-CH=CH-CH=CH_(2)`
C. `CH_(3)-CH=C=CH-CH_(3)`
D. `CH_(2)=CH-CH_(2)-CH=CH_(2)`

Explanation

To determine which of the given dienes is chiral, we need to analyze each compound for the presence of a plane of symmetry. A compound is chiral if it does not have a plane of symmetry. Let's go through the options step by step.

### Step 1: Analyze Compound A
- **Compound A**: CH3CH=CH=CH2
- This compound is an allene. In an allene, the central carbon atoms are sp-hybridized and the molecule can be represented as:
```
CH3 - C=C=C - H
```
- The two terminal groups (hydrogens) on one end are identical.
- **Conclusion**: There is a plane of symmetry in this compound. Therefore, it is **not chiral**.

### Step 2: Analyze Compound B
- **Compound B**: CH3CH=CH-CH=CH2
- This compound is a conjugated diene. The structure can be visualized as:
```
CH3 - CH = CH - CH = CH2
```
- The presence of the CH3 group in the plane means that there is a plane of symmetry that bisects the molecule.
- **Conclusion**: This compound has a plane of symmetry and is **not chiral**.

### Step 3: Analyze Compound C
- **Compound C**: CH3CH=C=CHCH3
- This compound can also be viewed as an allene with different groups at the terminal carbon atoms:
```
CH3 - C = C - CH3
```
- Here, both terminal carbons have different groups (CH3 and H).
- **Conclusion**: There is no plane of symmetry in this compound, making it **chiral**.

### Step 4: Analyze Compound D
- **Compound D**: CH2=CH-CH2-CH=CH2
- The structure can be represented as:
```
CH2 = CH - CH2 - CH = CH2
```
- This compound has a central carbon with two identical groups (hydrogens).
- **Conclusion**: There is a plane of symmetry in this compound, so it is **not chiral**.

### Final Answer
The only chiral compound among the given options is **Compound C**.