Question

(-)-1-chloro-1-phenylethane in toluene racemises slowly in the presence of small amount of $Sb{Cl}_5$, due to the formation of:

• A. cabanion
• B. carbene
• C. free-radical
• D. carbocation

Answer 1

Answer: (D)

carbocation

A planar cabocation is generated when $Sb{Cl}_5$ remove ${Cl}^{-}$ from the substrate.

Since the reactant is having chiral center.

This carbocation is subsequently attacked by ${Cl}^{-}$ (nucleophile) from both the sides (ie., from top and bottom) to produce a racemic mixture.

Option D is correct.