25. Condensation Chemistry

Predict the product of the following reactions.

(j)

What are the products of the following reactions?

i.

Show how the following compound can be prepared from starting materials that have no more than five carbons:

Predict the product of the following reactions.

(a)

Predict the product of the following reactions.

(c)

a. Propose a mechanism for the following reaction:

What is the major product of each of the following reactions?

b.

Propose a mechanism for the conjugate addition of a nucleophile (Nuc:^–) to acrylonitrile (H₂C=CHCN) and to nitroethylene. Use resonance forms to show how the cyano and nitro groups activate the double bond toward conjugate addition.

A Cannizzaro reaction is the reaction of an aldehyde that has no a-hydrogens with concentrated aqueous sodium hydroxide. In this reaction, half the aldehyde is converted to a carboxylic acid and the other half is converted to an alcohol. Propose a mechanism for the following Cannizzaro reaction:

Suggest a reagent and a reactant that could be used to form the following molecules by conjugate addition of a cuprate. There can be multiple possibilities.

(a)

What are the products of the following reactions?

j.

What is the major product of each of the following reactions?

a.

Propose a mechanism for the conjugate addition of a nucleophile (Nuc:^–) to acrylonitrile (H₂C=CHCN). Use resonance forms to show how the cyano activate the double bond toward conjugate addition.

What are the products of the following reactions?

g.