Conjugate Addition Reactions and Stork Enamine Synthesis

These flashcards cover key concepts and reactions related to conjugate addition reactions, including the specifics of Michael addition and the Stork enamine synthesis.

What is Michael addition?

A reaction where a nucleophile adds to an alpha-beta unsaturated carbonyl compound.

What do we call the product formed from the attack of a nucleophile at the beta position of an alpha-beta unsaturated aldehyde or ketone?

An enolate.

What is a Michael donor?

A doubly stabilized enolate that serves as a nucleophile in a Michael addition.

What is a Michael acceptor?

An alpha-beta unsaturated aldehyde or ketone that reacts with Michael donors.

What is the significance of the Stork enamine synthesis?

It allows the conversion of a carbonyl into an enamine that can participate in Michael addition reactions.

What is the first step in the Stork enamine synthesis process?

Treating a carbonyl compound with a secondary amine to form an enamine.

What are the three steps involved in the Stork enamine synthesis?

Formation of an enamine, Michael addition, hydrolysis.

Why are regular enolates not effective as Michael donors?

They are not stable enough to function as nucleophiles in Michael addition.

What is the outcome when both one-two and one-four addition are observed using an enolate as a nucleophile?

A mixture of products is formed.

In conjugate addition, why is the reaction specifically termed one-four addition?

Because the nucleophile and proton add across the one and four positions of a conjugated pi system.

What reducing agent can convert an aldehyde to a primary alcohol?

Lithium aluminum hydride (LiAlH4) followed by water.

How do we know if a compound is a Michael acceptor?

It will have an alpha-beta unsaturation and be an aldehyde or ketone.

What happens to the double bond in a Michael addition reaction?

It is lost when the nucleophile adds to the beta position.