Question

Which of the following is not an example of allylic halide?

• A. 4- chlorobut-1-ene
• B. 1- chlorobut-2-ene
• C. 3- chloro-2-methyl but-1-ene
• D. 4- chloropent-2-ene

Hint:

In allylic halides, the halogen should be attached to a carbon atom that is directly next to the carbon-carbon double bond.

Answer 1

The Correct Option is A

Allylic Halide Identification Problem

An allylic halide is a compound where the halogen atom is attached to a carbon atom that is adjacent to a carbon-carbon double bond. Let's analyze the options:

• 4- chlorobut-1-ene: The chlorine atom is attached to the carbon in the 4th position, which is not adjacent to the double bond, making it not an allylic halide.
• 1- chlorobut-2-ene: Here, chlorine is attached to the carbon in the 1st position, which is adjacent to the double bond (position 2), making this an allylic halide.
• 3- chloro-2-methyl but-1-ene: In this case, the chlorine is attached to the 3rd carbon, which is adjacent to the double bond, making it an allylic halide.
• 4- chloropent-2-ene: The chlorine is attached to the 4th carbon, which is adjacent to the double bond at the 2nd position, making this an allylic halide.

Conclusion:

Thus, the correct answer is 4- chlorobut-1-ene.