Exam 1 Name __________________________ CHEM 212 1. (18 pts) Complete the following chemical reactions showing all major organic products; illustrate proper stereochemistry where appropriate. If no reaction occurs, indicate “NR”: 2. (6 pts) Show which starting materials are used to produce the following Diels-Alder products:
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Exam 1 Name __________________________
CHEM 212 1. (18 pts) Complete the following chemical reactions showing all major organic products; illustrate proper
stereochemistry where appropriate. If no reaction occurs, indicate “NR”:
2. (6 pts) Show which starting materials are used to produce the following Diels-Alder products:
3. (8 pts) Name the following compounds using IUPAC conventions:
_____________________ _____________________ _____________________ _____________________
4. (6 pts) Propose a mechanism for the addition of HBr to 1,3-hexadiene. Show the intermediates that lead to each
product and indicate which is more stable. Indicate which product is thermodynamically favored and which is kinetically favored.
5. (8 pts) Draw all reasonable resonance structures for each species. Circle the structure which is the strongest
contributor/most stable resonance structure. a.
b.
c.
d.
6. (4 pts) Rank the following dienes in order of increasing heat of hydrogenation (1 – lowest to 4 – highest):
7. (8 pts) (8 pts) For each of the following compounds, indicate the number of resonances (not multiplicities) that would be observed on a
1H NMR spectrum:
____________ ____________ ____________ ____________ ____________ 8. (8 pts) For each of the following compounds, indicate the multiplicity of the resonance observed for the indicated
protons (shown Hs):
____________ ____________ ____________ ____________ 9. (6 pts) For each of the following molecules circle each set of magnetically unique protons. For each set indicate the
approximate chemical shift:
10. (18 pts) Give the structure that would produce each of the following three
1H NMR spectra. Circle your final answer
for grading. a.) C7H5O2Br – There is a
1H broad singlet at 12 ppm. The resonances below from left to right are a singlet, doublet,
doublet and triplet. All resonances integrate to 1H.
O
ONH
O
O
Br
H
CH2
O
CH2
O
CH3
b.) C5H10O. Eyeball measure integrals yourself! Region from 1-2.7 ppm is expanded for you.
c.) C5H8O
Score ________/100 Approx. Course Grade: ____
2H
1H
2H 3H
Exam 1 Name __________________________
CHEM 212 1. (18 pts) Complete the following chemical reactions showing all major organic products; illustrate proper
stereochemistry where appropriate. If no reaction occurs, indicate “NR”:
No reaction, not a conjugated diene
major
2. (6 pts) Show which starting materials are used to produce the following Diels-Alder products:
3. (8 pts) Name the following compounds using IUPAC conventions:
2-iodoaniline______ 2,4-octadiene____
4-bromo-2-ethyl-1-flouorobenzene 3-chlorobenzoic acid
4. (6 pts) Propose a mechanism for the addition of HBr to 1,3-hexadiene. Show the intermediates that lead to each
product and indicate which is more stable. Indicate which product is thermodynamically favored and which is kinetically favored.
5. (8 pts) Draw all reasonable resonance structures for each species. Circle the structure which is the strongest
contributor/most stable resonance structure. a.
b.
c.
d.
6. (4 pts) Rank the following dienes in order of increasing heat of hydrogenation (1 – lowest to 4 – highest):
3 1 2 4
7. (8 pts) (8 pts) For each of the following compounds, indicate the number of resonances (not multiplicities) that would be observed on a
1H NMR spectrum:
_________2___ 5 3 6 1 8. (8 pts) For each of the following compounds, indicate the multiplicity of the resonance observed for the indicated
protons (shown Hs):
___doublet___ ______quintet______ _____quartet_______ ____doublet________ 9. (6 pts) For each of the following molecules circle each set of magnetically unique protons. For each set indicate the
approximate chemical shift:
Aldehyde – 9.5, two aromatics
6.5-8.0, two aliphatics 2.0 and 1.0
3 aliphatics 1-2, 2 alkene 5.5-6.5,
HO from acid > 10
Terminal alkyne – 3.0, 2
aliphatics 2.0 and 1.0
10. (18 pts) Give the structure that would produce each of the following three
1H NMR spectra. Circle your final answer
for grading. a.) C7H5O2Br – There is a
1H broad singlet at 12 ppm. The resonances below from left to right are a singlet, doublet,
doublet and triplet. All resonances integrate to 1H.
meta substituted, acid proton at 12 – m-bromobenzoic acid
O
ONH
O
O
Br
H
CH2
O
CH2
O
CH3
b.) C5H10O. Eyeball measure integrals yourself! Region from 1-2.7 ppm is expanded for you.
HDI = 1 with an oxygen, suspect C=O. On one side a methyl (3H singlet at 2.0), on the other an isopropyl group
(septet at 2.4 and doublet at 1.1) c.) C5H8O
Alkene and aliphatic, HDI = 2 so alkene + another db or ring.
Score ________/100 Approx. Course Grade: ____
2H
1H
2H 3H
Exam 2 Name ___________________
CHEM 212 1. (36 pts) Complete the following chemical reactions showing all major organic products; illustrate proper
stereochemistry where appropriate. If no reaction occurs, indicate “NR”: a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
2. (8 pts) Consider the following substituted benzenes. For each example: a. Indicate whether the substituent is activating or deactivating (circle one) b. Indicate whether it would be ortho, meta or para directing (circle all that apply)
Activating Deactivating Ortho Meta Para
Activating Deactivating Ortho Meta Para
Activating Deactivating Ortho Meta Para
Activating Deactivating Ortho Meta Para
3. (6 pts) Nomenclature: Name the acids or provide a structure given the name. a.
b.
c. d.
Succinic acid Potassium 2,3,5-trifluorohexanoate
4. (4 pts) In preparing for this exam you may have consumed caffeine, which inhibits the retention
of short term memories (like organic exam chemistry knowledge). Is caffeine aromatic? State your reasoning.
5. (6 pts) Show how the following compound can be synthesized from the indicated starting material:
6. (8 pts) Show the contributing resonance structures following a para addition of an electrophile (E
+) to phenol. Circle
the most stable resonance structure or structures.
7. (6 pts) We studied the EAS reaction of benzene. There are many other families of aromatic compounds that also undergo EAS reactions. Suggest the probable course of the EAS reactions of thiophene (right).
a. Is the ring more or less electron rich than benzene? b. Would EAS reactions be faster or slower? c. What orientation of EAS would be most favored relative to the ring sulfur? Explain why. d. Draw the orbital diagram for thiophene; be sure to label all orbitals containing delocalized electrons and lone
pairs. 8. (12 pts) Indicate if the anions would deprotonate the acid in each pair (Circle yes/no):
g.
h.
i.
Yes No Yes No Yes No a.
b.
c.
Yes No Yes No Yes No d.
e.
f.
Yes No Yes No Yes No
9. (6 pts) Synthesize m-methoxybenzyl cyanide from m-methylanisole:
10. (8 pts) Circle the compounds that are aromatic; for those that are not aromatic, briefly state which of the four criteria are not met.
Approximate Course Grade: A A- B+ B B- C+ C D F Score ________/100
Exam 2 Name ___________________
CHEM 212 1. (36 pts) Complete the following chemical reactions showing all major organic products; illustrate proper
stereochemistry where appropriate. If no reaction occurs, indicate “NR”: a.
b.
NR – Friedel-Crafts conditions react with –
NH2
c.
d.
e.
f.
g.
h.
i.
j.
k.
2. (8 pts) Consider the following substituted benzenes. For each example: a. Indicate whether the substituent is activating or deactivating (circle one) b. Indicate whether it would be ortho, meta or para directing (circle all that apply)
Activating Deactivating Ortho Meta Para
Activating Deactivating Ortho Meta Para
Activating Deactivating Ortho Meta Para
Activating Deactivating Ortho Meta Para
3. (6 pts) Nomenclature: Name the acids or provide a structure given the name. a.
b.
c.
d.
Succinic acid Potassium 2,3,5-trifluorohexanoate
4. (4 pts) In preparing for this exam you may have consumed caffeine, which inhibits the retention
of short term memories (like organic exam chemistry knowledge). Is caffeine aromatic? State your reasoning.
All atoms in both the 6 and 5 membered ring are (or can) be sp2 hybridized.
Planar, cyclic
10 pi electrons – 2 nitrogens in 6-membered ring with lone pairs, double bond bridging rings, C=N double
bond in 5-membered ring and lone pair on N in 5-membered ring.
Aromatic!
5. (6 pts) Show how the following compound can be synthesized from the indicated starting material:
6. (8 pts) Show the contributing resonance structures following a para addition of an electrophile (E
+) to phenol. Circle
the most stable resonance structure or structures.
7. (6 pts) We studied the EAS reaction of benzene. There are many other families of aromatic compounds that also undergo EAS reactions. Suggest the probable course of the EAS reactions of thiophene (right).
a. Is the ring more or less electron rich than benzene? b. Would EAS reactions be faster or slower? c. What orientation of EAS would be most favored relative to the ring sulfur? Explain why. d. Draw the orbital diagram for thiophene; be sure to label all orbitals containing delocalized electrons and lone
pairs. a. Ring is more e- rich – 6 p electrons for 5 atoms vs. 6 for 6 in benzene. b. EAS is faster for more e- rich systems c. Ortho (2-) addition – additional resonance structure with sulfur
Each p-orbital on C has one e-, on sulfur it has two; second lone pair on sulfur in sp2 orbital
8. (12 pts) Indicate if the anions would deprotonate the acid in each pair (Circle yes/no):
g.
h.
i.
Yes No Yes No Yes No a.
b.
c.
Yes No Yes No Yes No d.
e.
f.
Yes No Yes No Yes No
9. (6 pts) Synthesize m-methoxybenzyl cyanide from m-methylanisole:
10. (8 pts) Circle the compounds that are aromatic; for those that are not aromatic, briefly state which of the four criteria are not met.
Approximate Course Grade: A A- B+ B B- C+ C D F Score ________/100
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