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Chem 2300

Exam 2

October 24, 2014

Name: (Please print)

(first) (last)

Last 4 digits of

A number

Score

I. Multiple Choice

( /30)

/90

II

/10

III

/10

Total score

/110

Note: Periodic table and pKa Values are on page 14.

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I. Multiple choice questions. (3 points each). Please put your answers on Scantron sheet. Your score will

be graded based only on your answers from Scantron sheet.

1. What is the systematic name for the following compound?

(a) (R)-5-methylcyclohexene

(b) (S)-4-methylcyclohexene

(c) (R)-4-methylcyclohexene

(d) (S)-5-methylcyclohexene

(e) None of the above

2. What is the systematic name for the following compound?

(a) (S)-3-fluorocyclohexene

(b) (Z)-3-fluorocyclohexene

(c) Cis-3-fluorocyclohexene

(d) (R)-3-fluorocyclohexene

(e) None of the above

3. What is the IUPAC name for the following compound?

(a) (R)-4-isopropyl-1-methyl-1-cyclohexene

(b) (S)-4-isopropyl-1-methyl-1-cyclohexene

(c) (S)-4-isopropyl-1-methylcyclohexene

(d) (S)-5-isopropyl-1-methylcyclohexene

(e) None of the above

4. What is the IUPAC name for the following compound?

(a) (R)-5-chloro-3-methyl-1-pentyne

(b) (S)-5-chloro-3-methyl-1-pentyne

(c) (R)-1-chloro-3-methyl-4-pentyne

(d) (S)-1-chloro-3-methyl-4-pentyne

(e) None of the above

5. What is the correct order of stability for the following alkenes (most to least)?

(a) I>II>III>IV>V

(b) II>I>III>IV>V

(c) III>II>I>IV>V

(d) V>IV>III>II>I

(e) None of the above

Cl

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6. What could be the major product for the following reaction?

(a) II, III

(b) I, V

(c) I, II, III, V

(d) II, III, IV

(e) None of the above

7. Which of the following are pairs of resonance structures?

(a) II, IV

(b) I, II, III

(c) III, IV

(d) II, III, IV

(e) None of the above

8. Arrange these carbocations in order of stability (most to least).?

(a) I>II>III>IV

(b) III>II>I>IV

(c) III>I>II>IV

(d) II>III>I>IV

(e) I>III>II>IV

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9. The second reaction in glycolysis involves the conversion of -D-glucopyranose 6-phosphate (I) to -

D-fructofuranose 6-phosphate (II) under the catalysis of phosphoglucoisomerase. Which of the

following can best describe the relationship between compound I and II?

-D-glucopyranose 6-phosphate -D-fructofuranose 6-phosphate

(a) They are structural isomer to each other.

(b) They are diastereomer to each other.

(c) They are enantiomer to each other.

(d) They are identical.

(e) None of the above

10. What could be the major product for the following reaction?

HBrmajor product?

(a) Br (b)Br

(c)Br

(d)Br

(e) None of the above

11. What will be the major product in its most stable conformation from the following reaction?

H2

Pd/Cproduct?

(a) (b) (c) (d) (e) None of the above

OH

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12. Brominated vegetable oil (BVO) has been used to stabilize citrus-flavored soft drinks since 1931. Its

high density helps the droplets of natural fat-soluble citrus flavors stay suspended in the drink. BVO can

be prepared by reacting vegetable oil, which contains unsaturated fatty acid, such as oleic acid, with

bromine. Without specifying the R group for the following representative structure of vegetable oil,

what will be the products from bromination?

(a) I, IV

(b) I, II

(c) III, IV

(d) II, III

(e) None of the above

13. Which of the following does not represent a pair of stereoisomer?

(a)and

(b)and

H3C

CH3H3C

CH3

(c)and

(d)and

HO

OH

(e) None of the above

14. Which of the following can best describe the relationship between compound I and II?

(a) They are structural isomer to each other.

(b) They are diastereomer to each other.

(c) They are enantiomer to each other.

(d) They are conformational isomers to each other.

(e) None of the above

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15. Which of the following compound is a meso compound?

H3C

CO2H

OH

OH

HO2C

CO2H

OH

OH

H3C

CO2H

OH

OH

HO2C

CO2H

OH

OH

I II III IV (a) I

(b) II

(c) III

(d) IV

(e) None of the above

16. Which of the following compound does not contain any chiral carbon?

(a) I

(b) II

(c) III

(d) IV

(e) None of the above

17. Which of the following are pairs of resonance structures?

(a) I, II, III, IV

(b) I, II, III, V, VI

(c) I, II, III, IV, V, VI

(d) I, III, IV, V

(e) None of the above

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18. Which of the following statements regarding the acidity of protons highlighted in bold are true?

(a) I, II, IV

(b) I, II, III

(c) I, III, IV

(d) II, III, IV

(e) None of the above

19. Which is a diastereomer to the compound circled in the box?

(a) I

(b) II

(c) III

(d) IV

(e) None of the above

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20. Which of the following statements are true?

(a) I, II, III, IV, V

(b) I, II, III, V

(c) I, III, IV

(d) I, IV

(e) None of the above

21. Which is a enantiomer to the compound circled in the box?

(a) I

(b) II

(c) III

(d) IV

(e) None of the above

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22. Coniine is a poisonous alkaloid found in poison hemlock and the yellow pitcher plant as a mixture of

R and S isomers. One method to separate the R and S coniine is by addition of a chiral acid and

separation of the salt of diastereomers by recrystalization, a process called resolution.

Which of the following acid can be used to achieve the separation of R and S coniine?

23. How many chiral carbons are present on sucrose?

(a) 7

(b) 8

(c) 9

(d) 10

(e) 11

24. Which compound has the most acidic proton highlighted in bold?

H H H H

I II III IV

(a) I

(b) II

(c) III

(d) IV

(e) None of the above

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25. What is order of decreasing acidity for the following carboxylic acids? (from the most to the least)

CO2H

CO2H CO2H

CO2H

I II III

IVV

H3CO H3C

CO2H

VI

CO2H

Br

O2N

CH3

O

(a) III>IV>V>VI>I>II

(b) III>I>IV>V>II>VI

(c) III>V>IV>VI>II>I

(d) III>V>II>VI>IV>I

(e) None of the above

26. Which of the following compounds are aromatic compounds?

(a) II, VI, VII

(b) I, IV, VII, VIII

(c) II, III, VI, VII

(d) II, IV, V, VIII

(e) None of the above

27. What is the correct order of decreasing reactivity (fastest to slowest) toward the electrophilic

aromatic substitution for the following compounds?

(a) I>II>III>IV

(b) II>I>IV>III

(c) III>II>IV>I

(d) IV>III>II>I

(e) None of the above

CO2H CH3 OCH3

I II III IV

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28. Aspirin can be prepared from salicyclic acid. What is the IUPAC (systematic) name of salicyclic

acid?

(a) o-hydroxyphenoic acid

(b) o-hydroxybenzoic acid

(c) m-hydroxybenzoic acid

(d) m-hydroxyphenoic acid

(e) None of the above

Based on the following synthetic scheme, answer question 29 – 30.

29. What could be reagent A?

(a) CH3COCl/AlCl3

(b) Cl2/FeCl3

(c) H2CrO4, H+, heating

(d) HNO3/H2SO4

(e) None of the above

30. What could be reagent B?

(a) CH3COCl/AlCl3

(b) Cl2/FeCl3

(c) H2CrO4, H+, heating

(d) HNO3/H2SO4

(e) None of the above

Continue to the Next Page

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II. The 7th

reaction in citric acid cycle is the conversion of furamate into malate, a hydration reaction

catalyzed by furamase. Provide an electron-pushing mechanism for this reaction and explain why H+

functions as a catalyst (Note: no need to involve furamase in the mechanism). The resulting malate is in

S configuration (assignment). Draw the specific structure of (S)-malate. (10 points)

Continue to the Next Page

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III. (Bonus) Propose an electron-pushing mechanism for the formation of compound II from I. (10

points)

Next Page: Periodic Table & pKa Values

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pKa Values for Some organic and Inorganic Acids

Acid Formula pKa Conjugate Base

Ethane CH3CH3 51 CH3CH2-

Ammonia NH3 38 NH2-

Ethanol CH3CH2OH 15.9 CH3CH2O-

Water H2O 15.7 HO-

Ethylammonium ion CH3CH2NH3+

10.64 CH3CH2NH2+

Bicarbonate ion HCO3-

10.33 CO32-

Phenol C6H5OH 9.95 C6H5O-

Ammonium ion NH4+

9.24 NH3

Carbonic acid H2CO3

6.36 HCO3-

Acetic acid CH3CO2H 4.76 CH3CO2-

Benzoic acid C6H5CO2H 4.19 C6H5CO2-

Phosphoric acid H3PO4 2.1 H2PO4-

Hydronium ion H3O+ -1.74 H2O

Sulfuric acid H2SO4 -5.2 HSO4-

Hydrogen chloride HCl -7 Cl-

Hydrogen bromide HBr -8 Br-

Hydrogen iodide HI -9 I-