Chem 232 Quiz 8 key

Chem 232
Discussion Section Quiz 8
D. J. Wardrop
wardropd@uic.edu
25 points, 20 min
Name:______________________________
Section Day/Time: _________________________
Question 1. 9 points
a. Rank in order of decreasing leaving group ability (1 = best leaving group; 5 = poorest leaving group).
Me
O
S O
O
F
H O Me
F 3 C
O
S O
O
Cl
2 5 4 1 3
5 Points
b. Rank each compounds/anions in order of decreasing nucleophilicity (1 = most nucleophilic; 5 = least
nucleophilic).
Me
O - Na + MeS - Na + MeOH MeO - Na +
Me
Me
3
1 4 2
4 Points
(go to next page)

Question 2.
Draw the major organic product for each of the reaction schemes below. Where appropriate, ensure that
you include the stereochemistry of the product. 16 points
Elimination
t-BuOK
OTs
S N 1
AcOH
O
O
t-BuOH
Answer
4 + 4 Points
Intramolecular
S N 2
S
OTs
OTs
Na
+ 2 S 2-
S
Intermolecular
S
OTs
S
R
(inversion)
Na
+ 2 S 2-
R R
S
C 6 H 12 S
S N 2
(inversion)
Answer
4 Points
1. BH 3 •THF;
NaOH, H 2 O 2
H
OH
Tosylation
of 1° alcohol
H
OTs
2. TsCl, pyridine
Hydroboration from
less hindered face
of alkene
S N 2 reaction
with cyanide (CN - )
3. NaCN, DMF
single diastereomer
H CN
C 12 H 21 N
New C-C Bond
Answer
4 Points