Identify the allyl chloride from the following:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) →
An allyl chloride is a compound in which chlorine is attached to an allylic carbon.
Allylic carbon = carbon adjacent to a C=C double bond.
General structure:
$CH_2=CH-CH_2Cl$
The Cl must be attached to the carbon next to the double bond, not directly on the double bond and not on aromatic ring.
Option-wise Explanation
Option 1
Cl is attached to side chain of benzene ring.
This is a benzyl chloride, not allyl chloride.
Option 2
Chlorine is attached to saturated ring carbon.
No adjacent double bond.
Not allylic.
Option 3
Chlorine is attached to carbon next to the double bond.
This is an allylic position.
Hence, allyl chloride.
Option 4
Chlorine is directly attached to carbon of double bond.
This is vinylic chloride.
Not allylic.