Question

Which one of the following is an allylic halide?

• A. 2-chlorobutane
• B. Chloroethene
• C. 3-bromopropene
• D. 2-chlorotoluene
• E. Dichloromethane

Hint:

Allylic = adjacent to double bond, Vinylic = directly on double bond.

Answer 1

The Correct Option is C

Understanding the Concept: An allylic halide is one in which the halogen atom is attached to a carbon atom adjacent to a carbon-carbon double bond.

Step 1: Define allylic position. \[ \text{Allylic position: } CH_2=CH-CH_2-X \]

Step 2: Check options.
• (A) No double bond → not allylic
• (B) Halogen directly on double bond → vinylic, not allylic
• (C) \(CH_2=CH-CH_2Br\) → halogen adjacent to double bond → correct
• (D) Aromatic substitution → not allylic
• (E) No double bond → not allylic Final Final Answer: \[ \boxed{\text{3-bromopropene is allylic halide}} \]