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CHEM 308.001/002 Dr. Alfred Amah
Sixth Examination
May 7, 2004
50 minutes 50 points
1. Draw structures(show hydrogens about all carbons, except for rings that may be shown
in the usual manner) that correspond to the following names: (6 points)
(a) 2, 4, 6-Trinitrophenol
(b) 2-Phenyl-2-propanol
(c) 3-Methyl-2-buten-1-ol
2. Acid-catalyzed dehydration of 2, 2-dimethylcyclohexanol yields 1,2-dimethylcyclohexene
as one of the major products. Write the complete stepwise mechanism for this reaction.
Show all electron flow with arrows and show all intermediate structures for full credit. (8
points)
CH3
OH
CH3
H3O+
CH3
CH3
2
3. Grignard Reagents. A highly useful and general method for the synthesis of alcohols is
the addition of Grignard reagents to carbonyl compounds. Show what Grignard reagent
and what carbonyl compound you would start with to prepare each alcohol below. List
two different possibilities for each compound. (12 points)
(a)
OH
C
CH2CH3
CH3
(b)
OH
CH2
C
CH3
CH3
3
4. Organic Products. Give the major organic product(s) of the following reactions or sequence of
reactions. Show all relevant stereochemistry.(12 points)
OH
(a)
OH
?
CrO3, H2SO4
THF
O
(b)
MgBr
1. ether
+
H
?
2. H3O+
Br
(c)
OH
(CH3)3SiCl
?
pyd.
CH3
(d)
OH
NaH
?
O
O
(e)
1. NaBH4, ethanol
OH
?
2. H3O+
O
(f)
1. (CH3)3SiCl, pyd.
?
2. CH3MgBr, ether
OH
3. H3O+
4
5. Give the reactant(s), product(s) or reagent(s) as indicated by the (?) in the following
synthetic scheme. Do not balance or show mechanism for each step. (12 points)
(a)
Br
O
?
1.
?
MgBr
?
2. H3O+
(b)
O
1. Hg(OAc)2 H2O
2. NaBH4
?
?
1.CH3CH2MgBr
2. H3O+
?