Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
NAME_______________________________ Course: Chem 231
Instructor: Larry Lee
REG.#:_______________________________
FINAL EXAMINATION – Spring 2010
CHEMISTRY 231
TO BE ANSWERED ON THE PAPER TIME: 3 hours
STUDENTS MUST COUNT THE NUMBER OF PAGES IN THIS EXAMINATION
PAPER BEFORE BEGINNING TO WRITE, AND REPORT ANY DISCREPANCY
IMMEDIATELY TO THE INVIGILATOR.
This examination consists of 17 pages INCLUDING this cover sheet. and
1
H NMR data sheet
MOLECULAR MODELS ARE PERMITTED
Total marks are 124 with 8 bonus marks and total time is 180 minutes.
Section Question Value Marks obtained
A 1 28
B
B
B
B
1
2
3
4
8
8
10
8
B
C
C
C
C
D
E
BONUS
Subtotal
5
1
2
3
4
1
1
1
5
5
8
6
4
24
10
8
132
Total
Final percent
124
1

d) e)
O a) b)
MARKS
Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
A. GENERAL CHEMISTRY DO 14 of 17 QUESTIONS
[28] 1. Draw the structure of the major organic product(s) formed in each of the following reactions. If no reaction occurs, indicate “N.R”. Account for all carbons.
O Na +
MgBr
Cl
Cl
O
Cl
CH c)
3
CH
2
O
OCH
2
CH
3
2 equivalents
H
3
O
CH
3
CH
2
OH
O HO OH
O O
O O
H
3
O
OH OH
O
O
H
2
N acid catalyzed
N
O O
OEt
+
OEt
Na OEt ethanol
OEt
OEt
O
O
2

Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
A. GENERAL CHEMISTRY DO 14 of 17 QUESTIONS f)
O
O
EtO
OEt
NaOEt
Ethanol
H
3
O
OEt
O
O g)
MgBr H
3
O
OH
O h)
O OH O
O O
H +
NaOH heat
O f or 1 mark
2 marks
O i)
O
Cl or
AlCl
3 limitation j) k)
O
O
H
2
NCH
2
CH
3
O
NCH
H
2
CH
3
O
+
H
O
H
NaOEt
EtOH
H
3
O heat
O OH f or 1 mark 2 marks
3

l)
EtO
O
Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
A. GENERAL CHEMISTRY DO 14 of 17 QUESTIONS
O
O O
NaOEt
EtOH
Br one equivalent
H
3
O heat
HO
1 mark
2 marks m)
O
OH MgBr
H
3
O ether
O n) o) p)
O
OH
O
NO
2
SOCl
2
N
Cl
AlCl
3
LDA
NR
O
CH
2
Cl H
3
O
Cl
O
LDA = Lithium diisopropyl amine q)
O
O
O
O
1. LiAlH
4
, THF
2. H
3
O
HOCH
2
CH
2
OH (two equivalents)
4

MARKS
Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
B. REACTIONS AND REAGENTS
[8] 1. Give the major organic reactant(s) that combined to give the best yield for the following products. a)
N
H
N
+
O b)
O O
O
O
+ c) d)
O
CH
3
CH
2
O
O
O
O
O
OCH
2
CH
3
CH
3
CH
2
O
O
O
N N HO
HO
O
A polyimide
O n
O
O
O
OCH
2
CH
3
O
O
OH
OH
+
Br
NH
2
NH
2
Br
5

MARKS
Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
[8] 2. The following products were obtained from an Aldol condensation reaction: Give the
Donor (nucleophile) and the Acceptor (electrophile) – Label the two reactants. a)
O
O
+
O b)
O O
O
2
H
+ c) d)
O
O OH
O
H
O or
O
O O
H
O
+ H
6

Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
MARKS B. REACTIONS AND REAGENTS
[10] 3. Selectivity is an important part of conceiving and carrying out organic transformations.
For each of the following, give the reagent which must be used in order to perform the indicated change. Assume acid work up follows each reaction. a)
2
CuLi b)
O
O H
O
OH
NaBH
4
HO c)
O
HO
O
O
CrO
3
O
H
H
3
O d)
O
OH
OH
O
H
3
CO CH
3
H
3
O
O
O
OH
O
H
3
C O
O
OH
7

Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
MARKS
[8] 4. The structure of the sex pheromone [attractant] of the female tsetse fly has been confirmed by the following synthesis. Compound D appears to be identical to the natural pheromone in all respects [including the response of the male fly]. Provide structures for A, B, C and D. O
A
BrCH
2
C
(CH
2
)
7
H
CH
2
2 catalyst
Br
Ph
3
P CH
2
(CH
2
)
7
CH
2
2 PPh
3 diethyl ether
D
C
PPh
3
37
H
2Br
76
A
C
2 n-BuLi
H
3
C(H
2
C)
11
B
2 CH
3
(CH
CH(CH
2
)
7
CH
2
)
11
(CH
2
)
11
CH
3
C
B
Ph
3
P CH(CH
2
)
7
CH PPh
3
D
H
3
C(H
2
C)
11
CH
2
(CH
2
)
7
CH
2
(CH
2
)
11
CH
3
[5] 5. As written, each of the following syntheses has a flaw or flaws. What is wrong with each one? (Briefly give one reason). a) b)
CH
3
Wrong starting material
Should be CH
3
Cl, AlCl
3
1. Cl
2
, FeCl
3
2.
KMnO
4
, NaOH, heat
3.
DiBAH, H
3
O
Does Ester to aldehydes
Can't do Carboxylic acids
H
CH
3
O
CH
3
1.
O
Cl ,
AlCl
3
2. HNO
3
, H
2
SO
4
3. H
2
, Pd, ethanol
CH
3
CH
2
CH
3
Use Wolf f -Kishner or Zn(Hg) with acid work up
NO
2
8

Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
MARKS C. MECHANISM AND CONCEPTS
[6] 1a) The Fischer project of Mannose is shown below. Use the Haworth framework given
(on the right) to redraw Mannose as Haworth projection in the correct stereochemical orientation
O
CH
H
HO H
H O OH
HO H
H OH
CH
2
OH
OH
OH
OH H
HO H
CH
2
OH
H H b) Answer the following questions with respect to the structures above i) Is Mannose a D or L sugar? L ii) Is the Haworth projection that you drew an ∝ -anomeric or β -anomeric?
β -anomeric
MARKS C MECHANISM AND CONCEPTS
[8] 2 Use the Huckel rule to determine whether each of the following compounds will exhibit aromaticity or not. Clearly indicate aromatic or not aromatic. Briefly give your reason.
Also note, lone pair of electrons are not shown on the heteroatoms (N, O, S).
H H
S
O
N
N
H H
H
8 π e- not aromatic 10 π e- aromatic 2 π e aromatic 6 π e- aromatic
does not follow rule flat follows rule flat , n = 0 n=1
9

Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
MARKS
[6] 3 Give the complete detailed stepwise mechanism, using curved arrows, and show all intermediates for the following reaction
O
+ H
2
N trace H
3
O
N
+ H
2
O
[4] 4 Give the complete detailed stepwise mechanism, using curved arrows, and show all intermediates for the following reaction
O
O
O Na OH
O Na + CH
3
CH
2
OH
10

Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
MARKS D SYNTHESIS. [8 marks each]: DO ONLY THREE OF FOUR
[24] 1. Complete the syntheses shown below, using the indicated starting materials and any other necessary reagents, solvents, etc., remembering that you must make any organometallic reagents you wish to use [This refers to RMgX, RLi, not LiAlH
4, etc].
Each synthesis may be carried out in five or less steps. Don't forget to show products for each step for full marks. a) f rom
O
H and CH
3
Br
H
3
O as the only source of Carbons.
Any other inorganic reagent can be used.
CH
2
=PPh
3 nBuLi
H
3
C PPh
3
CH
3
Br
PPh
3
O
CrO
3
OH
H
3
O
Br
PBr
3
Pyridine
OH
NaBH
4
O
H
3
O
H
MgBr
11

Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
MARKS D SYNTHESIS. [8 marks each] DO ONLY THREE OF FOUR b)
O
O O O
From or
O
N
EtO OEt OEt or O O and HN(CH
3
)
2 as the amine and any other organic compound containing three or less carbons and any inorganoc reagent.
EtO
O O
OEt
NaOEt
CH
3
CH
2
Br
EtO
O O
OEt
H
3
O
HO
N
O
O
O
O
OH
HO
2 HN(CH
3
)
2
Cl
O
SOCl
2 pyridine
12

MARKS D SYNTHESIS. [8 marks each] DO ONLY THREE OF FOUR
Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee c)
O
CH
From benzene and any other necessary organic and inorganic reagents
H
N
O
CH
3
NO
2
NH
2 O
O
O
HN
O
HNO
3
H
2
SO
4
Sn
HCl
CH
3
Cl
AlCl
3
O
O
CH
H
N
O
CH
3
DIBAH
HN
COOCH
3
CH
3
OH
H
3
O
HN
O
COOH
H
3
O KMnO
4
OH , heat
HN
CH
3
O
13

Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
MARKS D SYNTHESIS. [8 marks each] DO ONLY THREE OF FOUR d)
OH O
Cl f rom
H CH
3
CH
3
CH
2
OH and any other necessary inorganic reagents
H
O
CH
3
+
H
O
CH
3
NaOH
Heat H
O
Mg
MgCl
O
CH
3
CH
2
MgCl
KMnO
4
H
3
O
Mg
OH
SOCl
2
CH
3
CH
2
Cl
Pyridine
CH
3
CH
2
OH
OH
H
3
O
Cl
14

Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
MARKS E Spectroscopy.
[10] Give answers in the space provided for the following molecule (note letters are added for clarity in answering the questions);
1.
H
3
H a
C
3
C c b
CH d e
3
O
CH f
2
CH g
2
O
Cl
CH h
CH i
3
How many distinct carbons are there in this molecule? 7
2.
3.
4.
How many
13
C NMR resonance signals are expected?
Which carbon resonance signal should be the furthest
7 downfield
How many distinct hydrogens are there in this molecule? 5
in
13
C NMR? e
5.
6.
7.
What is the expected spin-spin
1
H NMR coupling pattern for the CH
(give pattern and relative intensity). 1:1 doublet
Which proton resonance signal should be the furthest upfield in
1
3
(labeled i)?
H NMR? a,b,c set
Relative intensity
Sketch an approximate
1
H NMR spectrum. Give the relative positions for each distinct proton (the exact position is not relevant) No need for integration. i a,b,c g f h
7 6 5 4 3 2 1 0
ppm
15

Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
BONUS Question (8 markts)
This is eight mark bonus question: No marks deducted for not completing this section.
Molecule (1) with the molecular formula C
4
H
6
Cl
2
O is treated with methanol to give molecule (2). The 1HNMR of Molecule (2) is given below:
C
4
H
6
Cl
2
O + CH
3
OH Molecule (2)
Molecule (1)
Analyze the
1
HNMR spectrum of Molecule (2), then determine and give its structure.
Give the structure of Molecule (1). Assign all peaks (what Hydrogens are causing what peak – for full marks)
For the spectrum above from left to right the peaks appear as (Singlet, triplet, triplet, multiplet)
Molecule 2 has 1 DBE: Good for a carbonyl
16

Chemistry 231 – Organic Chemistry 2 – Camosun College – June 2010 L.Lee
Table 13.3 Correlation of 1H Chemical shift with Environment
Type of Hydrogen Chemical Shift ( δ ) Type of Hydrogen Chemical Shift ( δ )
- END of FINAL -
17