Question

The correct statement for $\alpha$ elimination is?

• A. It forms cyclic compounds
• B. It forms carbine or substituted carbine
• C. Two atoms are removed from $\alpha$ and $\beta$ positions
• D. In $CHC{l}_3;\alpha$ elimination is not possible

Answer 1

Answer: (B)

It forms carbine or substituted carbine

α elimination (eliminations in which both the proton and the leaving group are located on the same atom) follow a mechanism akin to an E1cB β-elimination. A strong base removes an acidic proton adjacent to an electron withdrawing group to give a carbanion. Loss of a leaving group from the carbanion creates a carbene. One of the best known elimination reactions occurs when chloroform is treated with base, forming a dichlorocarbene.