Arrange the following in the decreasing order of leaving group ability:
(I) -OAc (II) -OMe (III) -OSO2Me (IV) CF3SO2O-
Answer & explanation
Correct answer: option 2
Weaker the base better is the leaving group. Now acidity decreases in the order : CF3SO2OH > MeSO2OH > AcOH > MeOH, therefore basicity of their conjugated bases increases in the reverse direction, i.e., CF3SO2O- < MeSO2O- < AcO- < MeO-