21. Aldehydes and Ketones: Nucleophilic Addition

What are the products of the following reactions?

e.

f.

Draw structures of the following derivatives.

(f) the methyl hemiacetal of formaldehyde

For each compound,

1. name the functional group.

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

(b)

Explain why acetals do not react with nucleophiles.

Propose a mechanism for each of the following reactions:

b.

Which ketone forms the most hydrate in an aqueous solution?

Which of the following are a. hemiacetals? b. acetals? c. hydrates?

2.

What are the products of the following reactions?

f.

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

Propose a mechanism for the acid-catalyzed hydrolysis of cyclohexanone dimethyl acetal.

Propose a mechanism for the acid-catalyzed reaction of cyclohexanone with ethylene glycol to give cyclohexanone ethylene acetal.

Draw structures of the following derivatives.

(d) the ethylene acetal of hexan-3-one

Show what alcohols and carbonyl compounds give the following derivatives.

(a)

(b)

(c)

Propose a mechanism for the acid-catalyzed hydrolysis of cyclohexanone ethylene acetal.

Propose a mechanism for the acid-catalyzed hydrolysis of the acetal given in Problem 18-26(f).