Q.54a - Organic Chemistry (Mcmurry)

Question

Question: The reactions shown below are unlikely to occur as written. Tell what is wrong with each, and predict the actual product.

a.

Step-by-Step Solution

Answer

Answer

                                                           Elimination reaction 

Step 1: S N 2 reaction

It is a nucleophilic substitution reaction in which an old bond is broken and a new bond is formed both processes occur simultaneously. Hence, it’s a single-step reaction.

The two reacting species are involved in the rate-determining steps.

The S_N2  reaction occurs with the primary alkyl halide but here the alkyl halide is secondary so that’s why S_N2 reaction cannot occur and these products are wrong:

Step 2: E 2 reaction

It is a nucleophilic elimination reaction in which an old bond is broken and a new bond is formed both the process occur simultaneously and no intermediate is formed.

Here, the carbon-hydrogen or halogen bond breaks to form a new double bond. Hence, it’s a single-step reaction.

E2 reaction occurs with the secondary alkyl halide where deprotonation of hydrogen occurs with the removal of halide ion and alkene formation occurs as shown:

                              Elimination reaction