Download 1 Chemistry 3720 Exam 2 Spring 2001 This exam is worth 100

Chemistry 3720
Exam 2
Spring 2001
This exam is worth 100 points out of a total of 600 points for Chemistry 3720/3720L. You have 50 minutes to
complete the exam and you may use the spectroscopy data sheet as needed. Good Luck.
1. (15 pts) Give the major products from each step in the following synthetic sequences.
1. Na2Cr2O7, H2SO4
H2O
a.
OH
2. CH3CH2NH2
catalytic H
b.
+
1. NaH, THF
OH
2.
O
3. H3O
+
1. PDC, CH2Cl2
2. Ph3P=CH2
c.
OH
3. H2SO4, H2O
d.
1. H2SO4, ∆
OH
2. xs HI, ∆
1. Na2Cr2O7, H2SO4
H2O
e.
OH
2. xs CH3OH, H
+
1
2. (10 pts) Provide a detailed mechanism for the following reaction.
O
O
xs H2O
O
H+ (catalyst)
3. (10 pts) Provide a detailed mechanism for the following reaction sequence to produce the alkene shown.
O
OH
1. Na2Cr2O7, H2SO4, H2O
2. m-CPBA, CH2Cl2
2
O
4. (15 pts) Provide the major organic products from each step in the following sequences.
a.
1. OsO4, t-BuOOH,
NaOH
2. NaIO4
b.
O
1. 2 CH3MgBr
O
2. H3O+
c.
1. m-CPBA
2. LiAlH4, THF
O
3. H3O+
d.
1. m-CPBA, CH2Cl2
2. CH3MgBr, THF
3. H3O+
e.
1. PDC, CH2Cl2
OH
2. xs CH3OH, H+
3
5. (10 pts) Design an efficient synthesis of the following product using 1-butanol as the only source of
carbon. You may use any of the reactions and reagents used so far in 3719 or 3720. Show a complete
retrosynthetic analysis of the problem, then the synthetic steps required to produce the compound in the
forward direction. Note: There is more than one correct way of solving this problem.
O
6. (15 pts) Provide the missing products in the following roadmap.
H2SO4, H2O
Na2Cr2O7
H2SO4, H2O
IR : 3300 cm-1
1. NaH, THF
2. CH3CH2Br
m-CPBA
CH2Cl2
xs HBr, ∆
13
2 products
4
C : 175 ppm
7. (5 pts) What product would you expect to be major when cyclopentyl methyl ketone is treated with
m-CPBA in CH2Cl2?
8. (10 pts) Design a synthesis of the product shown using cyclohexene and methanol as the only organic
starting materials. You only need to show a retrosynthesis if it helps you plan your synthetic scheme.
O
CH3
5
9. (10 pts) Provide the organic products from each step in the following reaction sequence.
OH
1. Na2Cr2O7, H2SO4, H2O
2. m-CPBA, CH2Cl2
3. 2 CH3MgBr, THF
+
4. H3O
6