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Chemistry 11 Fall 2013
Examination #3 PRACTICE TEST1 ANSWER KEY
1.
Consider the structure of a derivative of N-demethylglycopyrrolate shown below, a drug
that reduces the production of saliva in patients that suffer from excessive drooling:
N-demethylglycopyrrolate derivative
H
OH
N
O
O
O
O
N
A.
Identify the SIX functional groups present (exclude the benzene ring).
1)
2)
3)
alcohol
ester
amine
4) amide
5) alkene
6) ether
B.
Determine the molecular formula of N-demethylglycopyrrolate.
C22H30N2O5
C.
Circle one answer in each row that so that your response best describes the
OC=O bond angle in N-demethylglycopyrrolate.
Trigonal planar
45
60
tetrahedral
90
trigonal pyramidal
109.5
linear
120
Now circle the phrase(s) below that correctly describe(s) Ndemethylglycopyrrolate.
optically active
optically inactive
1
chiral
achiral aromatic
bent
180
D.
H
OH
N
O
O
O
O
N
Add, subtract, or otherwise change NO MORE THAN 3 ATOMS (in the above structure)
to create a new molecule that contains a ketone as a functional group.
Answer: Lots of possibilities here. Can change amide group to a ketone. Can
change tertiary amine to a ketone.
2.
A.
Clearly label all the stereocenters in the structure shown below, labeling each one
as either R or S.
O
N
O
R
B.
R
How many diastereomers are possible for N-demethylglycopyrrolate? 2
How many enantiomers are possible for N-demethylglycopyrrolate? 1
Draw one enantiomer and one diastereomer of N-demethylglycopyrrolate in the
box below (if they exist; otherwise, write NOT POSSIBLE and briefly explain):
2
H
H
O
O
N
N
O
O
ENANTIOMER
3.
DIASTEREOMER
In pharmaceutical chemistry, molecules with similar structures will often
be synthesized in attempt to find more effective drugs or to eliminate unwanted
side effects. Drawn below is a structural analog of N-demethylglycopyrrolate,
called Molecule A.
Molecule A
OH
O
CH3
RO
CH3
=
O
NH2
NH2
CH3
CH3
Draw the most stable and least stable chair conformations of Molecule A. (Hint:
you may wish to abbreviate a portion of Molecule A as an "R" group for
simplicity, but you must clearly identify your abbreviation.)
CH3
CH3
RO
CH3
CH3
OR
NH2
NH2
MOST STABLE
LEAST STABLE
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4.
consider Molecule B below, another derivative of Ndemethylglycopyrrolate. Draw the expected Fischer Projection for this derivative
molecule in the box. (You may abbreviate the benzene ring as "phenyl".)
N
OH H3C
Br
OH
=
CH3
OH
CH2
Cl
H
Br
N
Molecule B
OH
Cl
H
CH
5.
CH2
NOMENCLATURE! Use the appropriate IUPAC notation to name or draw each of the
organic structures below:
A.
trans-1,4-dibutylcyclohexane
CH2CH2CH2CH3
H3CH2CH2CH2C
B.
6-ethyl-2-methyl-4,4-dipropyloctane
C.
cis-1,2-diethylcyclopropene
4
I
HO
D.
1
E.
8
F
m-fluoroiodobenzene
trans-3-methyl-6-propyl-6-octen-2-ol
5-methyl-2-heptyne
F.
6.
REACTIONS! Draw the expected reactant or product for each reaction below, and
write the accompanying mechanism where requested. If no reaction is expected to occur,
write "NR".
5
Cl
A.
HCl
Show mechanism:
H
Cl
Cl
OH
B.
H2O
H2SO4
Show mechanism:
H
HO
H
OH2
excess H2
Pt
C.
D.
Br2
CHBr3
NR; aromatic
E.
Br2
CHBr3
H2
Pd
OH
F
+
O2
6
OH2
7.
Fill-in the following chart below with respect to the three listed drugs:
Medicinal/Pharmaceutical
Use?
Drug
Effective for the treatment
of high blood pressure and
congestive heart failure
Active as a pain and fever
reliever
Used to treat morning
sickness and found to be
useful in the treatment of
leprosy and may also be
useful in the treatment of
AIDS
Captopril
Ibuprofen
Thalidomide
8.
S-enantiomer
Racemic Mixture
R-enantiomer (as S is found
to be teratogenic)
Arrange the following compounds in order of expected increasing boiling point, and
briefly explain your ordering:
<
<
9.
Manufactured? (i.e., Renantiomer/Senantiomer/Racemic
Mixture)
<
<
A. List all the intermolecular forces that need to be overcome for the compound A
given below to boil?
H
OH
N
O
O
O
O
N
7
.
B.
LDF, dipole-dipole, hydrogen bonding
For each of the molecules below , circle whether you would expect it to have a
higher or lower boiling point than compound A above. Briefly explain your
answer.
OH
HO
O
N
H
NH2
HIGHER
LOWER
This molecule has an aromatic ring in place of cyclohexane in compound A.
Aromatic ring is more stable and hence boiling point is higher.
OH
HO
O
HIGHER
LOWER
Two amine groups are replaced by methyl. So lower hydrogen bonding in this
molecule. Hence lower boiling point.
8