Chapter 19, Problem 19.42P

Interpretation Introduction

Interpretation:

The synthesis for the given intermediate from the compound A has to be proposed.

Concept introduction:

Enamine:

An enamine is a compound where the lone pair of electrons in the nitrogen atom of $C-N$ bond gets delocalized by the presence of nearby $C=C$ bond.

It is formed by the reaction of a ketone or aldehyde and a secondary amine under acidic conditions with the elimination of water molecule.

Stork Enamine reaction:

In the reaction, enamine formation from a ketone or aldehyde occurs. Then the addition of this enamine to an alkyl halide or ketone is done. The alkylated enamine is hydrolysed to get starting ketone or aldehyde.