24. Enolate Chemistry: Reactions at the Alpha-Carbon

Provide the major product after each step for the following reaction.

Which of the following can NOT be formed through the stork enamine reaction with 2-butanone? 

Without looking back, propose a mechanism for

the hydrolysis of this iminium salt to the alkylated ketone.

The first step is attack by water, followed by loss of a proton to give a carbinolamine. Protonation on nitrogen allows

pyrrolidine to leave, giving the protonated ketone.

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Write equations showing the expected products of the following

enamine alkylation and acylation reactions. Then give

the final products expected after hydrolysis of the iminium salts.

(c) piperidine enamine of cyclopentanone + methyl iodide

Describe how the following compounds could be prepared from cyclohexanone using an enamine intermediate:

a. <IMAGE>

What reagents should be used to prepare the following compounds?

c. <IMAGE>

Show how you would accomplish each conversion using an enamine synthesis with pyrrolidine as the secondary amine.

(c) <IMAGE of reaction>