Question

The allylic halide, among the following is:

• A. \( R - \text{CH} - R \)
• B. \( \text{CH}_2 - \text{CH} - \text{X} \)
• C. \( \text{C}_6\text{H}_5 - \text{X} \)
• D. \( \text{CH}_2 - \text{CH} - \text{CH}_2 - \text{X} \)

Hint:

Allylic halides have a halogen attached to a carbon adjacent to a double bond, which is key to their reactivity in substitution reactions.

Answer 1

The Correct Option is B

Step 1: Understanding Allylic Halides.
Allylic halides are compounds where a halogen is attached to a carbon atom adjacent to a double bond (the allylic position). The structure \( \text{CH}_2 - \text{CH} - \text{X} \) is an example of an allylic halide. Step 2: Analyzing the Options.
- (A) \( R - \text{CH} - R \): This is not an allylic halide because it doesn't have a halogen attached to the allylic carbon. - (B) \( \text{CH}_2 - \text{CH} - \text{X} \): Correct. This is an allylic halide because the halogen is attached to the carbon next to the double bond. - (C) \( \text{C}_6\text{H}_5 - \text{X} \): This is not an allylic halide because it is an aryl halide. - (D) \( \text{CH}_2 - \text{CH} - \text{CH}_2 - \text{X} \): This is not an allylic halide because the halogen is not directly attached to an allylic carbon. Thus, the correct answer is (B).