CHE 175
Spring, 2002
QUIZ 3
Name___________________________
ID (SSN)________________________
Instructor_______________________
SHORT ANSWER (10 pts each)
1. Rank the following compounds in order of decreasing acidity (1 = most acidic à 5 =
least acidic):
O
O
O
O
O
H
N
O
O
2. Show the enol tautomer of 1,3,5-cyclohexatrione. Would you expect this compound
to exist predominantly in the keto or enol form?
O
O
O
3. Show the major product that's formed from each of the reaction sequences shown
below with cyclohexanone.
1. Me2NH
2. CH3CH2I
O
1. LDA, -78 °C
2. CH3CH2I
3. H2O, H+
4. Show a mechanism for the acid-catalyzed α-bromination of acetone.
5. Show how you would carry out the following synthesis.
O
O
MULTIPLE CHOICE (10 pts each)
6. What is the carbon nucleophile that attacks molecular bromine in the acid-catalyzed
α-bromination of a ketone?
(a) an enolate
(b) a carbocation
(c) an acetylide
(d) an enol
7. The Hell-Volhard-Zelinsky reaction involves:
(a) the α-bromination of carboxylic acids
(b) the α-bromination of ketones
(c) the bromination of alcohols
(d) none of the above
O
(a)
O
H
(b)
H
O
H
(c)
H3C
H3C
(d) all of these
CH 3
8. Which of the following compounds does NOT have an α-hydrogen?
9. Which of the following is a β-ketoester?
O
OH
(a)
O
(b)
O
OEt
O
O
O
(c)
(d)
O
10. What is the major product of the following reaction?
O
1. LDA, -78 °C
2. CH3 I, -78 °C
O
(a)
O
(b)
O
OH
(c)
(d)
**Bonus (+5 pts): Explain what "LDA" is, how to make it, and what it's used for.
O
O