Q.63 - Organic Chemistry

Question

Draw a stepwise detailed mechanism that illustrates how four organic products are formed in the following reaction.

Step-by-Step Solution

Answer

The mechanism for the formation of the substitution and elimination products are shown below:

The carbocation formation is stable here, and the resonance condition is also present. As a result, different kinds of elimination and substitution products are formed.

Types of bases or nucleophiles used

Weak bases and weak nucleophiles such as methanol promote a mixture of both  ${\mathbf{\text{S}}}_{\mathbf{\text{N}}}\mathbf{\text{1}}$ and E1 reactions. Here water is used, which acts both as a weak base and weak nucleophile. As a result, they give a mixture of both   ${\text{S}}_{\text{N}}\text{1}$ and E1 reactions.

Types of substrates used

Tertiary halides undergo a  ${\text{S}}_{\text{N}}\text{1}$ and E1 reaction respectively when a weak nucleophile and a weak base are used, such as water observed in this reaction.

Similarities in both the reaction pathway

Both  ${\text{S}}_{\text{N}}\text{1}$ and E1 reaction is a two-step process, and carbocation formation is the rate-determining step.

 

By considering all the steps, the mechanism for the formation of the substitution and elimination products are shown below:-

 

Different kinds of products are formed due to the delocalization of pi-electrons inside the 6-membered ring.

Representation of the detailed reaction scheme