Q60. - Organic Chemistry

Question

Question: Draw stepwise mechanisms illustrating how each product is formed.

Step-by-Step Solution

Answer

Answer

 

The stepwise mechanism of reaction with LDA is given as: 

Formation of the major product

                     Formation of one minor product

          Formation of the other minor product

 The stepwise mechanism of reaction with KOC(CH₃)₃ is  (CH₃)₃COH given as :

           Formation of a major and a minor product

Step 1: Potassium t-butoxide

Potassium t-butoxide is a sterically hindered base for attacking carbon.

It is stronger and non-nucleophilic base.

The mechanism followed is E2 as elimination occurs.

 

Step 2: Stepwise Mechanism

The stepwise mechanism of reaction with LDA is given as: Abstraction of the proton from terminal carbon followed by the removal of bromine ion results in the formation of a cyclic major product.

                      Formation of major product. 

  Abstraction of the proton from non-terminal carbon and removal of the HBr gives one minor product.

                             Formation of one minor product.

 Carbonyl group undergoes resonance to form enol, abstraction of proton then results in the formation of another cyclic minor product

                  Formation of other minor product.  

The stepwise mechanism of reaction of KOC(CH₃)₃ in (CH₃)₃COH  is given as:

                    Formation of a major and minor product.