Chapter 8, Problem 68P

Interpretation Introduction

Interpretation:

A mechanism for the reaction given below is to be proposed based on the mechanism of reactions of halogens with alkenes.

Concept Introduction:

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Halogen adds across a double bond to forma cyclic halonium intermediate. The halide ion left over from the first step can then launch a nucleophilic attack to form a vicinal dihalide.

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If the reaction is work out in a polar nucleophilic solvent or another functional group that can act as a nucleophile is present in a suitable position, it may attack the halonium ion instead of the left over halide ion.