Download Chem 14C Lecture 2 Spring 2016 Exam 1 Page 1

Chem 14C Lecture 2
Spring 2016
Exam 1
Page 1
Page 5 is an information and scratch paper page. You may carefully detach it from the rest of
the exam. Page 5 will be discarded prior to grading. Nothing on page 5 will be graded.
1. (18) How many of the following are present in prednisone (structure on page 5)? Write a number in each blank.
(a) Hydrogen atoms: ___________
(b) sp3 carbon atoms that are also stereocenters: ___________
(c) sp2 carbon atoms: ___________
(d) Atoms with p orbitals: ___________
(e) Pi electrons: ___________
(f) Total number of stereoisomers (including the structure shown): ___________
(g) Number of enantiomers of the structure shown: ___________
(h) Number of diastereomers of the structure shown: ___________
(i) Number of diastereomers of the structure shown that are also meso compounds: ___________
2. (3) Write all of the functional groups present in prednisone. If a functional group appears more than once, write
its name just one time.
3. (2) Write an appropriate letter in the blank. The absolute configuration of the prednisone carbon labeled as
"question 3" is ________________.
O
CH3
O
4. (2) On the structure given here circle all of the conjugated atoms.
Draw in any conjugated atoms that are not specified, if
necessary.
OH
OH
H
H3C
H
H
H
H
O
H
5. (2) Complete this statement by writing a number in the box. Based on the answer to question 4,
how many atoms of prednisone always lay in the same plane due to conjugation?
6. (6) Complete the following statement writing 'is' or 'is not' in the blank. If you write 'is', you are done with this
question. If you write 'is not' then complete the sentence by adding no more than ten words.
Prednisone ________________ aromatic because...
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Chem 14C Lecture 2
Spring 2016
Exam 1
Page 2
O
In order to find molecules that have the same desirable effects as
certain drug, but less of its undesirable effects, many analogs of the
drug might be prepared. Analogs are molecules whose structures are
similar to the initial structure. Molecule A is one such prednisone
analog.
OH
CH3
O
H3C
OH
H
H
H
O
Molecule A
7. (6) In the space below write all of the words that describe the relationship between prednisone and molecule A?
Answer choices: Constitutional isomers, conformational isomers, configurational isomers, stereoisomers,
enantiomers, diastereomers, meso compounds, not isomers, and cannot determine from information given.
8. (6) In the space below each list write the one word or phrase from each set that applies to molecule A.
(a) Chiral, achiral, neither of these, or cannot be determined from information given.
(b) Optically active, optically inactive, neither of these, or cannot be determined from information given.
(c) Dextrorotatory, levorotatory, neither of these, or cannot be determined from information given.
9. (6) Another prednisone analog was produced by reducing its most reactive carbonyl group with NaBH4:
O
CH3
O
Prednisone
NaBH4
H3C
CH3CH2OH
H
H
O
OH
OH
CH3
HO
H3C
or
H
H
H
OH
OH
H
O
HO
Molecule B
Molecule C
Complete this statement by writing B or C in the blank, then add no more than twenty words: The most likely
structure for the prednisone analog produced by carbonyl reduction is molecule _______ because this molecule...
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Chem 14C Lecture 2
Spring 2016
Exam 1
Page 3
Yet another prednisone analog, called an oxime, has the structure shown below. The wavy line
'molecule beyond this point unimportant for this question'.
means
H3C
H3 C
HO-NH2
HO
N
O
Prednisone
Oxime
10. (2) Complete the oxime drawing shown above by drawing in all lone pairs for the atoms shown.
11. (6) In the boxes labeled contributor E and contributor F, draw two additional resonance contributors for the
oxime. Less significant resonance contributors will earn less significant credit.
H3C
HO
N
Oxime Contributor D
Oxime Contributor E
Oxime Contributor F
12. (2) Write a letter (D, E, or F) in the blank: The most significant oxime resonance contributor is contributor ____.
13. (4) Complete this sentence by adding no more than ten words. Your explanation must use only one reason to
explain both less significant contributors. Be very precise and very specific.
The one reason why both contributors that I did not write in question 12 are not the most significant is...
14. (4) Complete this drawing of the oxime resonance hybrid by adding all partial pi
bonds, lone pairs, and all δ and all δ charges. There are exactly four δ charges.
You may need to consider some contributors that you did not draw in question
11.
++
H3C
−
HO
N
15. (2) Rank the electronegativity of the elements that form the oxime by writing one element symbol (U, Ag, etc.)
in each blank. If two or more elements have the same electronegativity, write those elements in the same blank.
Most electronegative → _________ > ___________ > __________ > ___________ ← Least electronegative
16. (2) Complete this equation by writing a number in the blank:
(Number of conjugated atoms in prednisone oxime) - (number of conjugated atoms in prednisone) = ________.
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Chem 14C Lecture 2
Spring 2016
Exam 1
Page 4
Pills prepared for oral drug delivery contain, in addition to the active drug, a number of ingredients such as
flavorings, dyes, and binders. A binder is like a glue of sorts, causing the pill's components to stick together.
Molecule G is a small portion of a high molecular weight molecule that might be used as a binder, or as the basis
from which the binder is manufactured.
CH2OH
CH2OH
O
O
O
HO
CH2OH
O
O
HO
OH
OH
O
O
HO
OH
Molecule G
17. (4) Write the name of the monosaccharide in molecule G. Be precise. Hint: The name includes four bits of
information about the monosaccharide's molecular structure.
18. (2) In the space below write the single best description of the monosaccharide in molecule G. Answer choices:
Aldohexose, aldopentose, ketohexose, ketopentose, or none of these.
19. (4) Assume for this question that molecule G includes exactly 2,000 monosaccharides in its structure. Complete
the following statement by writing a number in each blank:
Molecule G has ___________ anomeric carbons and ___________ hemiacetals in its structure.
20. (2) Molecule G is a polysaccharide. The one-word name of this polysaccharide is ______________________ .
21. (5) Write 'is' or 'is not' in the blank, then complete the sentence by adding no more than twenty words: Molecule
G _________ easily digestible by humans because...
22. (10) This question has nothing to do with prednisone, its analogs, or molecule G. For each molecule below, write
'is' or 'is not' in the blank. If you write 'is' you are done with this molecule. If you write 'is not' complete the
explanation by adding no more than ten words.
This molecule _____________ aromatic because...
(a)
This molecule _____________ aromatic because...
O
(b)
This molecule _____________ aromatic because...
(H3C)3C
(c)
C(CH3)3
(H3C)3C
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Chem 14C Lecture 2
Spring 2016
Exam 1
Page 5
Information and Scratch Paper Page
You may carefully remove this page from the exam. This page will be discarded prior to
grading. Nothing on this page will be graded.
Prednisone (shown below) is a glucocorticoid steroid prodrug that is used to treat certain inflammatory diseases
(such as asthma, COPD, and severe allergies) and (at higher does) some types of cancer. The drug must be
prescribed with caution, however, because it may have significant adverse side effects. In order to make counting
easier, the same structure is repeated several times.
O
CH3
O
H3C
O
OH
OH
H
O
Question 3
H
CH3
H3C
H
H
O
O
CH3
O
H3C
O
OH
OH
CH3
O
Question 3
H
H
H3C
H
OH
OH
Question 3
H
H
O
H
O
O
CH3
O
H3C
O
OH
OH
CH3
O
Question 3
H
H
H3C
H
OH
OH
Question 3
H
H
O
H
O
O
CH3
O
H3C
O
OH
OH
CH3
O
Question 3
H
H
O
Question 3
H
H
O
OH
OH
H3C
H
OH
OH
Question 3
H
H
H
O
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