Question

Which of the following compound is not allylic chloride?

• A. \(\mathrm{CH_2{=}CH-CH_2Cl}\)
• B. \(\mathrm{CH_3-CH{=}CH-CH_2Cl}\)
• C. Chlorocyclohexene with chlorine directly attached to the double-bond carbon
• D. Cyclohexene derivative having chlorine on the carbon adjacent to the double bond

Hint:

Allylic halide: halogen on the carbon adjacent to a double bond. Vinylic halide: halogen directly attached to the double-bond carbon.

Answer 1

The Correct Option is C

Step 1: Understand the meaning of allylic chloride.
An allylic chloride is a compound in which the chlorine atom is attached to an \(\mathrm{sp^3}\) carbon atom that is adjacent to a carbon-carbon double bond. In simple words, chlorine should be on the carbon next to the double bond, not on the double-bonded carbon itself.
Step 2: Differentiate allylic chloride from vinylic chloride.
If chlorine is attached directly to a carbon atom involved in the double bond, then the compound is called a vinylic chloride, not an allylic chloride. This is the key point needed to solve the question.
Step 3: Analyse the given options.

• (A) \(\mathrm{CH_2{=}CH-CH_2Cl}\): Chlorine is on the carbon adjacent to the double bond, so it is an allylic chloride.
  
• (B) \(\mathrm{CH_3-CH{=}CH-CH_2Cl}\): Again, chlorine is on the carbon next to the double bond, so it is allylic chloride.
  
• (C) In this structure, chlorine is directly attached to a double-bond carbon of the ring. Therefore, it is a vinylic chloride, not an allylic chloride.
  
• (D) Here chlorine is attached to the carbon adjacent to the double bond in the ring, so it is allylic chloride.
  

Step 4: Conclusion.
Hence, the compound that is not an allylic chloride is option \((C)\), because it is a vinylic chloride.
Final Answer:Option (C).