Chem 322 Exam 2 2020
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Chem 322 Exam 2
Winter 2020
1. (15 points) The spectra below correspond to five of the compounds listed at the bottom. Draw the appropriate compound next to each spectrum. No compound is used more than
once.
OH
OH
O
O
O
O O
CH3 O
O
N
N
O
OH
2. (20 points) Predict the major organic product or products for the following. Be sure to indicate stereochemistry where appropriate. "No reaction" may be an answer. Assume each of these is in the most appropriate solvent.
a)
O
a) LDA
b) CH3Cl
O
a) NaOH
b) H+ workup
O
OCH3
N
H
O
HO 
OH
5. (16 points) Fill in the missing reagents for this multi-step synthesis.
O
O
O
6. (10 points) Design a multi-step synthesis to achieve the following in two or more steps.
steps
Br
OH
7. (11 points) Draw a mechanism for the following transformation (orthoester hydrolysis).
O
O
O
H+ , H2O
O
R OH
OH
HO
1. (15 points) The spectra below correspond to five of the compounds listed at the bottom. Draw the appropriate compound next to each spectrum. No compound is used more than once.
|
|
|
O
OH
|
|
OH
|
|
O
O
|
OH
OH
O
O
O
O O
CH3 O
O
N
N
O
OH
2. (20 points) Predict the major organic product or products for the following. Be sure to indicate stereochemistry where appropriate. "No reaction" may be an answer. Assume each of these is in the most appropriate solvent.
a)
O
a) LDA
b) CH3Cl
a) NaOH
b) H+ workup
|
O
OCH3 |
3. (6 points) How many signals would you see in the 13C NMR of each of these.
|
4 |
4. (22 points) An unknown with the formula C11H10O2 has the spectra shown below. Answer the questions on the next page.
4, continued. (22 points) An unknown with the formula C11H10O2 has the spectra shown on the previous page. Answer the questions below.
a) How many degrees of unsaturation does this compound have?
7
b) In the IR, what does the signal at ~2200 suggest?
triple bond
c) Is there a type of bonding that you can definitely rule out based on the IR?
OH bond (either alcohol or carboxylic acid) - also no aldehyde C-H bond or sp C-H bond
d) Does this compound have symmetry?
yes
e) In the 13C NMR, what does the chemical shift of the signal at ~170 suggest? Please be specific about what the chemical shift suggests.
sp2 hybridized carbon double bonded to oxygen
f) In the 13C NMR, what does the ORD splitting data for the signal at ~170 suggest? Please be specific about what the ORD splitting data suggests.
no hydrogens on this carbon
g) In the 1H NMR, what does the chemical shift of the signal at ~4.2 suggest? Please be specific about what the chemical shift suggests.
hydrogen on an sp3 carbon connected to oxygen
h) In the 1H NMR, what does the integration of the signal at ~4.2 suggest? Please be specific about what the integration suggests.
2 identical hydrogens (e.g. CH2 group)
i) In the 1 H NMR, what does the splitting pattern of the signal at ~4.2 suggest? Please be specific about what the splitting pattern suggests.
next to 3 identical hydrogens (e.g. next to CH3 group)
j) Draw the structure for the unknown in the box.
|
O
O
|
5. (16 points) Fill in the missing reagents for this multi-step synthesis.
O
O
|
a) LDA O
|
O
PPh3
heat
6. (10 points) Design a multi-step synthesis to achieve the following in two or more steps.
steps
Br
OH
O
OH
O
Br
OH
Br
OH
KMnO4
KOH
heat
Br2
FeBr3
a) LiAlH4
b) H+
7. (11 points) Draw a mechanism for the following transformation (orthoester hydrolysis).
H+ , H2O
OH
HO
H+
H
R O
O
O
R 
O 
O H
H
O
O
O
H 
H O O 
R
O
H
O
H
H
O O 
O
H
O
H
H
H
O
O
H O O H
H
O 
H
O
H O
O H
H+
2022-08-12