ORGANIC CHEMISTRY I
60 POINTS
BEFORE YOU BEGIN, TAKE A MOMENT TO WRITE DOWN HERE TWO THINGS ON THIS EXAM
THAT YOU ARE CONFIDENT THAT YOU UNDERSTAND:
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**TAKE A BREATH**
QUESTION 1: Draw the most stable carbocation that has the formula C5H9+. (5 points)
QUESTION 2: Classify each of the following reactions as substitution, elimination or addition. (8 points)
O
O
N
N
H
F
__________________________
__________________________
HN
H
3
C
CH
3
N
CH
3
H
3
C
O
H
3
C
O
Ph
I
O
O
CH
3
O
O
H
3
C
Two types of reaction:
__________________________
O
N
O
CF
3
O
N
O
F
MgBr
__________________________ QUESTION 3: Fill in the blanks for the following reactions. (3 points per blank – 18 points)
OH
HS
CH
3
N
+
+
O
CH3
intermediate
H
2
SO
4
,
H
2
O
H3C
CH3
CH
3
H
Br
OH
CH3 CH3
QUESTION 4: Predict whether Compound M has a pKa closer to that of 1-butanol or to that of butanoic acid. Explain your reasoning. (4 points)
Compound | pKa |
1-Butanol (C4H10O)
| 16 |
Butanoic Acid (C4H8O2)
| 4.8 |
Compound M (C4H6O2) O H3COH |
|
QUESTION 5: This compound has three possible conjugate bases. Draw each of them. (6 points)
conjugate
base
#2
conjugate
base
#3
conjugate
base
#1
O
HO
H
Cl
H
2
N
O
QUESTION 6: Which position on this molecule is the most acidic? Justify your answer. (3 points)
O
H2N
O
Cl
H HO
QUESTION 7: Draw the conjugate acid and conjugate base in the following reaction. Which side of the equilibrium is favored? You must explain your reasoning to receive full credit. (4 points)
O O
O
O
+ ?
F3CCF3 H3CCH3 H H
QUESTION 8: Draw the mechanisms for the following reactions. Show all necessary arrows and intermediates. (4 points each – 12 points)
H CH3CH3
O
O
O
O
+ CH3 + CH3
O
HO
H C CH3 H-Br H3C Br CH3
3
H3CH3C
O
H
3
C
S
Cl
O
,
H
2
O
S
O
O
H3C OH
CH3H3CCH3
H3CCH3
CH3