2025 Spring CHEM 0320 Name__________________________
Exam 2 Page 1
I. (34 points) Complete each of the following reaction schemes. Complete structures are required;
if a reagent has a common abbreviation, then the abbreviation can be used but must be completely
correct. Sequential steps should be numbered. Include stereochemistry as appropriate. If
stereoisomeric products form, draw one and write “+enantiomer” or “+diastereomer” In the box.
H 2N
(S)
OH O
O N OH O
1a. + (S)
(R) OH heat N O
O (R) N
H O
+ H 2O -1 for missing stereochem 6
any chemically
O O logical strong base O O
1b. H CO P H3CO P
3
O
H3CO H3CO NH
3
NH
O
+4 for connectivity
+2 for stereochemistry 6
1) Li
Cl Cl O Cl O
2) CO2 SOCl2
1c. OH Cl
3) H3O+ (workup)
Cl Cl Cl Cl Cl Cl
5 4
-1 for missing stereochem
OCH3
OCH3 1) 2 eq CH3Li OCH3
I
1d. OCH3
O
O 2) H3O+ (workup) OH
-1 for missing stereochem 5 C11H20O2 5
, 2025 Spring CHEM 0320 Name__________________________
Exam 2 Page 2
II. (26 points) Complete each of the following reaction schemes. Complete structures are required.
Include stereochemistry as appropriate. If stereoisomeric products form, draw one and write
“+enantiomer” or “+diastereomer” In the box.
2a. Cyclopeptidic natural products featuring a glutamate-derived quinazolin-3,6-dione framework exhibit a
diverse array of biological activities, including anticancer, anti-HIV, and antimalarial properties. Here shows
a few steps to install a new functional group.
N N
N N
NaCN
N N + NaBr
O O
O O
-1 for missing stereochem Br 5 CN
O
H2O, 40 °C
F3C OH
N
N
N
O
O
-1 for missing stereochem O NH2 5
2b. Lancilactone C was isolated from the stems and roots of Kadsura lancilimba, which have been
traditionally used in Chinese folk medicine. Recently, the total synthesis and structure including relative
stereochemistry was reported. Here are a few steps to manipulate carbonyl functional groups.
1) CH3MgBr
O DIBAL-H O
O
O O –78 °C HO
O 2) H3O+ (workup)
+ HOCH2CH3 5 5
2c. Draw the structure of (S,E)-2-chloropent-3-enoic acid.
(S,E)-2-chloropent-3-enoic acid
O
5 carbons +1
carboxylic acid on C1 +1
OH
alkene on C3 +1
Cl on C2 +1 Cl
C2 (S) +1
trans alkene +1 6
Exam 2 Page 1
I. (34 points) Complete each of the following reaction schemes. Complete structures are required;
if a reagent has a common abbreviation, then the abbreviation can be used but must be completely
correct. Sequential steps should be numbered. Include stereochemistry as appropriate. If
stereoisomeric products form, draw one and write “+enantiomer” or “+diastereomer” In the box.
H 2N
(S)
OH O
O N OH O
1a. + (S)
(R) OH heat N O
O (R) N
H O
+ H 2O -1 for missing stereochem 6
any chemically
O O logical strong base O O
1b. H CO P H3CO P
3
O
H3CO H3CO NH
3
NH
O
+4 for connectivity
+2 for stereochemistry 6
1) Li
Cl Cl O Cl O
2) CO2 SOCl2
1c. OH Cl
3) H3O+ (workup)
Cl Cl Cl Cl Cl Cl
5 4
-1 for missing stereochem
OCH3
OCH3 1) 2 eq CH3Li OCH3
I
1d. OCH3
O
O 2) H3O+ (workup) OH
-1 for missing stereochem 5 C11H20O2 5
, 2025 Spring CHEM 0320 Name__________________________
Exam 2 Page 2
II. (26 points) Complete each of the following reaction schemes. Complete structures are required.
Include stereochemistry as appropriate. If stereoisomeric products form, draw one and write
“+enantiomer” or “+diastereomer” In the box.
2a. Cyclopeptidic natural products featuring a glutamate-derived quinazolin-3,6-dione framework exhibit a
diverse array of biological activities, including anticancer, anti-HIV, and antimalarial properties. Here shows
a few steps to install a new functional group.
N N
N N
NaCN
N N + NaBr
O O
O O
-1 for missing stereochem Br 5 CN
O
H2O, 40 °C
F3C OH
N
N
N
O
O
-1 for missing stereochem O NH2 5
2b. Lancilactone C was isolated from the stems and roots of Kadsura lancilimba, which have been
traditionally used in Chinese folk medicine. Recently, the total synthesis and structure including relative
stereochemistry was reported. Here are a few steps to manipulate carbonyl functional groups.
1) CH3MgBr
O DIBAL-H O
O
O O –78 °C HO
O 2) H3O+ (workup)
+ HOCH2CH3 5 5
2c. Draw the structure of (S,E)-2-chloropent-3-enoic acid.
(S,E)-2-chloropent-3-enoic acid
O
5 carbons +1
carboxylic acid on C1 +1
OH
alkene on C3 +1
Cl on C2 +1 Cl
C2 (S) +1
trans alkene +1 6
