21. Aldehydes and Ketones: Nucleophilic Addition

Show what amines and carbonyl compounds combine to give the following derivatives.

(e)

For each compound,

1. name the functional group.

2. show what compound(s) result from complete hydrolysis.

(g)

Propose a mechanism for the acid-catalyzed reaction of benzaldehyde with methanol to give benzaldehyde dimethyl acetal.

Can the rate of hydrate formation be increased by hydroxide ion as well as by acid? Explain.

Draw structures of the following derivatives.

(b) the semicarbazone of cyclobutanone

As discussed in Section 17.9.1, alkenes can be hydrogenated selectively in the presence of ketones. Suppose that was not the case, and suggest how you might use a protecting group strategy to generate A from B.

Show how you would accomplish the following synthetic conversions efficiently and in good yield. You may use any necessary additional reagents and solvents.

(d)

Suggest a series of steps involving a cuprate reagent that would convert the reactant on the left to the product on the right. The ideal number of steps is shown.

(b)

Solving the following road-map problem depends on determining the structure of A, the key intermediate. Give structures for compounds A through K.

Propose mechanisms for the following reactions.

(f)

Give the nitrile and organometallic reagent you would use to make the following ketones. There are two possible answers for both.

(a)

Show how you would synthesize the following derivatives from appropriate carbonyl compounds.

(d)

Show how Wittig reactions might be used to synthesize the following compounds. In each case, start with an alkyl halide and a ketone or an aldehyde.

(c) Ph–CH=CH–CH=CH–Ph

(d)

Predict the product of the following reaction sequences.

(b)

Show how you would accomplish the following syntheses efficiently and in good yield. You may use any necessary reagents.

(b)