The most predominant product that gives an overall yield of 90 % for the given reaction has to be drawn. Concept Introduction: Carbonyl compound when treated with LDA (Lithium Diisopropylamide) undergoes deprotonation at the α -carbon to form enolate. The enolate formed is resonance stabilized as the negative charge will be spread over other atoms too. The resonance stabilized intermediate undergoes reaction with other molecule of carbonyl (same or different) to form the respective products. If LDA is used as a base the less substituted α carbon is deprotonated due to steric hindrance. Deprotonation of α carbon to form enolate Nucleophilic attack of enolate S N 2 reaction with alkyl halide

Question

The following compound may be synthesized through alkylation of an appropriate enamine with an alkyl bromide, followed by hydrolysis of the resulting immonium ion. Using this strategy, provide the necessary starting materials for the synthesis. (Note that a portion of the starting enamine is given.)

Answer 1

Question

Chapter 19, Problem 19.80P

Interpretation Introduction

Interpretation:

The most predominant product that gives an overall yield of 90% for the given reaction has to be drawn.

Concept Introduction:

Carbonyl compound when treated with LDA (Lithium Diisopropylamide) undergoes deprotonation at the α-carbon to form enolate. The enolate formed is resonance stabilized as the negative charge will be spread over other atoms too. The resonance stabilized intermediate undergoes reaction with other molecule of carbonyl (same or different) to form the respective products. If LDA is used as a base the less substituted α carbon is deprotonated due to steric hindrance.

Deprotonation of α carbon to form enolate

Nucleophilic attack of enolate

S_N2 reaction with alkyl halide

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The following compound may be synthesized through alkylation of an appropriate enamine with an alkyl bromide, followed by hydrolysis of the resulting immonium ion. Using this strategy, provide the necessary starting materials for the synthesis. (Note that a portion of the starting enamine is given.)

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