MolSynapsequestion bank
MolSynapse / Question bank / Organic Reaction Mechanisms III: Nucleophilic Substitution / Neighbouring group participation
JEE Main levelSingle correct optionDifficulty 2 of 3o3139

Assertion (A): cis-2-Acetoxycyclohexyl tosylate solvolyses much more slowly than the trans isomer. Reason (R): In the cis isomer the acetoxy group cannot reach the back side of the carbon bearing the tosylate group.

  1. ABoth A and R are true, and R is the correct explanation of A
  2. BBoth A and R are true, but R is not the correct explanation of A
  3. CA is false but R is true
  4. DA is true but R is false

Answer: A

The assertion is true. The reason is also true and explains it: the intramolecular displacement requires the participating group to attack anti to the leaving group, and in the cis isomer (one axial, one equatorial substituent) this geometry is not available, so no anchimeric acceleration occurs.
Practice Organic Reaction Mechanisms III: Nucleophilic Substitution More on Neighbouring group participation
Previous questionNext question

More questions on Neighbouring group participation