ORGANIC CHEMISTRY I (CHEM 2242) EXAM #3
OCTOBER 23, 2020 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
F
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Two types of reaction:
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__________________________ QUESTION 3: Fill in the blanks for the following reactions. (3 points per blank – 18 points)
CH3
H3C
CH3
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)
QUESTION 6: Which position on this molecule is the most acidic? Justify your answer. (3 points)
O
H2N
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
+ ?
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
+ CH3 + CH3
H C CH3 H-Br H3C Br CH3
H3CH3C
O
H3C OH
CH3H3CCH3
H3CCH3
CH3