You MUST also complete ALL the information at the top of this page.

CHEM 2OA3

Test 1 October 20, 2006

VERSION 1

NAME:_______________________

ID#:_____________

Lab Station:______

Please circle your lab section.

Group Tut. Room Monday Tuesday Wednesday Thursday Friday

ABB 162 L01 L02 L03 L04 L05

I

ABB 270 L18 L19 L20 L21 L22

ABB 162 L13 L14 L15 L16 L17

II

ABB 270 L06 L07 L08 L09 L10

Duration: 90 minutes

Instructors: Drs. Harrison and Brook

This examination paper consists of 18 pages, containing 20 (twenty) multiple choice (MC) questions, and 4 short answer questions. You are responsible for ensuring your copy of the question paper is complete. A mini-periodic table and spectral correlation charts are provided on the last two pages.

Answer all the MC questions on optical scan sheets. There are no part marks and you will not be penalized for incorrect answers. Each MC question is worth two marks. Follow the instructions on the optical scan sheets, and the University rules for OMR exams which are reproduced on page 2. Failure to follow instructions may result in loss of credit. Scan sheets will not be re-marked under any circumstances. You are responsible for ensuring all answers are in the correct place, and that you follow the correct procedure for filling out the scan sheet.

Print your name, student number, course name, section number and date in the spaces provided on page 1 of the form. Section 01 is Dr. Brook’s group; section 02 is Dr. Harrison’s. You MUST sign the sheet in the space marked signature.

Mark your student number in the space provided on the sheet on Side 1 AND FILL IN THE CORRESPONDING BUBBLES UNDERNEATH.

Now enter your version number, which can be found on the top right hand corner of this page, by filling in the BUBBLE in the “version” column provided. Finally, BUBBLE in your section number. Now CHECK all of your entries.

Begin answering questions using the first set of bubbles, marked "1". DO NOT USE SIDE 2.

All McMaster rules and procedures relating to Academic Dishonesty and Academic Integrity apply to this exam; all violations will result in a penalty. Students must do their own work. A program designed to detect similar answers will be used for this exam.

OMR EXAMINATION – STUDENT INSTRUCTIONS

NOTE: IT IS YOUR RESPONSIBILITY TO ENSURE THAT THE ANSWER SHEET IS PROPERLY COMPLETED. YOUR EXAMINATION RESULT DEPENDS UPON PROPER ATTENTION TO THESE INSTRUCTIONS.

The scanner, which reads the sheets, senses the shaded areas by their non-reflection of light. A heavy mark must be made, completely filling the circular bubble, with an HB pencil. Marks made with a pen or felt-tip marker will NOT be sensed. Erasures must be thorough or the scanner may still sense a mark. Do NOT use correction fluid on the sheets. Do NOT put any unnecessary marks or writing on the sheet.

1. Print your name, student number, course name, section number and the date in the space provided at the top of Side 1 (red side) of the form. Then the sheet MUST be signed in the space marked SIGNATURE.

2. Mark your student number in the space provided on the sheet on Side 1 and fill in the corresponding bubbles underneath.

3. Mark only ONE choice from the alternatives (1,2,3,4,5 or A,B,C,D,E)

provided for each question. If there is a True/False question, enter response 1 (or A) as True, and 2 (or B) as False. The question number is to the left of the bubbles. Make sure that the number of the question on the scan sheet is the same as the question number on the test paper.

4. Begin answering questions using the first set of bubbles, marked “1”.

Questions 1-20; 2 marks each.

1. Which of the following compounds is (2S)(E)-3-propyl-non-4-enone?

O O

H O

H O

CH₃ O

C9

A B C

D E

A) A B) B C) C D) D E) E

2. Which of the following pairs of compounds are constitutional isomers?

Br

Br

Br Br

H Br

Br H

Cl Cl

i

iii iv

ii

v

3. Which orbital drawing best represents the carbonyl π orbital of propenoic acid (acrylic acid)? O O H O O H O O H O O H O O H A B C D E

A) A B) B C) C D) D E) E

4. Which of the following is THE LEAST reasonable resonance structure for methyl propenoate acid (methyl acrylate)?

O O CH₃ O O+ CH₃ C O+ O CH₃

C+ O

O CH₃

C+ O

O CH₃

A B

C

D E

A) A B) B C) C D) D E) E

5. Which of the following compounds has torsional (twist or ring) strain but NO angle strain?

A B C D E

(Flat)

6. Which of the following statements is(are) FALSE about the molecular orbital diagram for the two bonds in the C=C double bond in butene (H2C=CH-CH2CH3)?

A B C D

E sp2 _{+ p orbital sp}2 _{+ p orbital}

i) The 2 p electrons in butadiene are located in orbital B

ii) Excitation of the molecule (using light for instance) would promote an electron from π bonding MO B to π* antibonding orbital C

iii) The MO, D, is the least stable orbital, and is the antibonding σ* orbital iv) The MO, A, is the most stable bonding π orbital

v) B represents the relative energy of electrons in the π* orbital

A) i, ii B) i, iv, v C) ii, iii D) iii, iv E) iv, v

7. Which of the following are resonance structures of compound 1?

O O NH₃ O OH NH₂ O O NH₃ O O NH₃ O OH NH₃ O O NH₂ 1

i ii iii

iv v + -+ -+ -+

8. The longest conjugation in the following compound extends over how many atoms? NH₂ O N N+

A) 2 B) 3 C) 6 D) 8 (E) 11

Questions 9-13 relate to daunomycin, an important anticancer compound, whose structure is shown below, along with a bond angle θ found inside the box marked :

O O

O C

H₃ OH

OH CH₃ O O sugar OH θ

(1)

a

b

9. What functional group is marked a in compound (1)?

(A) ketone (B) alcohol (C) ester (D) ether (E) aldehyde

10. What functional group is marked b in compound (1)?

(A) ketone (B) alcohol (C) ester (D) ether (E) aldehyde

11. Which functional group gives rise to the acidic character of compound acid (1)? (A) methyl (B) phenol (C) ether (D) sp2 C-H (E) carboxylic acid 12. The bond angle θ in the box shown in compound (1) is approximately:

(A) 60 o (B) 90o (C) 109 o (D) 120 o (E) 180 o

13. The hybridizations of the carbonyl carbon and the methyl carbon in the group marked a, are, respectively:

(A) sp and sp2 _{(B) sp}2 _{and sp}2 _{(C) sp}3 _{and sp}2 _{(D) sp}2 _{and sp}3 _{(E) sp}3 _{and sp}2

14. Which of the following structures has one chiral centre of R configuration?

15. Which of the following statement(s) is/are TRUE?

A. The carbon-13 NMR chemical shift in ppm of chloromethane is larger than that of bromomethane because bromine is a less electronegative atom

B. The carbon-13 NMR chemical shift in ppm of chloromethane is larger than that of bromomethane because bromine is a more electronegative atom

C. The carbon-13 NMR chemical shift in ppm of chloromethane is smaller than that of bromomethane because bromine is a less electronegative atom

D. The carbon-13 NMR chemical shift in ppm of chloromethane is smaller than that of bromomethane because bromine is a more electronegative atom

E. Bromine and chlorine are both halogens and so will have identical effects on the carbon-13 chemical shift in ppm

16. What is the major organic species present in solution when compound 1 is treated with 1 molar equivalent of aqueous HCl?

O SO₃ NH₂ OH SO₃ NH₂ OH+ SO₃ NH₂ O

SO₃H NH₂ O

SO₃ NH3+

OH

SO₃ NH2

H

1 i ii iii

iv v

--

--

-A) i B) ii C) iii D) iv E) v

17. Which of the statements is(are) FALSE about the following structure?

O O CH3

CH₃ a

b

c

d

i) If the ring is flipped to the other chair conformation, methyl group c will become equatorial

ii) Reduction of ketone d to the alcohol is easier than ketone a because of steric hindrance

18. The LEAST stable rotamer of 1,2-dibromopropane, viewed along the C1 to C2 bond, is: H H Br Br Me H Br H Me Br H H H Br H Me Br H Me Br H Br H H Me Br H H H Br

A) B) C) D) E)

19. Which of the following equilibria have a K>1?

OLi O

H Na

H

C

H₃ S OH O O OH O H H Na O _H

3O+ OH H₂O

C

H₃ S OLi O O

+

+

+

+

+

+

A) i, only B) i and ii C) ii only D) ii and iii E) iii only

20. Which of the statements below is(are) FALSE about the following equilibrium?

CH₃ R CH₃ R K A B

i) For R = iPr, K < 1, but for R = Me, the equilibrium constant K = 1 ii) Compounds A and B are both trans isomers.

iii) The R group in compound B is equatorial

CH₃ CH₃

(1)

21. [15] When 3,4-dimethyl-cyclohex-3-en-1-one (1) is reduced, several possible products can be formed: one molar equivalent of hydrogen can be added to either functional group, or else two molar equivalents of hydrogen can add, to reduce both functional groups. Answer the following questions about the reduction of 1.

(a) When 1 is treated with H2 and a palladium catalyst, the alkene is reduced, but

not the ketone. Draw the structure of the product in the space provided. (2)

O

CH₃ CH₃

(1) (Product)

H₂, Palladium

(b) This reaction proceeds such that the two hydrogen atoms that are added are cis to one another in the product. Complete the diagram below to show the correct conformation of the product.

(You MUST complete the structure to show ALL substituents at C-1, C-3 and C-4, you MUST make the carbon atom numbers correspond between starting material and product, i.e. as numbered, AND the substituents must be drawn correctly, otherwise no marks!) (3)

O

CH₃

CH₃

C H₃ 1

3

4

1

3 4

(c) Is this product achiral, OR is it formed as a single enantiomer, OR is a racemic mixture produced? (1)

(d) For the structure you drew in (b), circle the correct answer for the absolute configuration of C-3 and C-4, according to the Cahn-Ingold-Prelog rules, or state that the centre is not chiral (achiral): (4)

C-3 R

S

achiral

(e) Suggest a reagent that would reduce the carbonyl group in 1. (2)

(f) Some reagents reduce both the alkene and carbonyl groups of 1. The addition to the alkene is still cis. One product of this reaction has S configuration at C-1, and the substituents at C-1 and C-3 are cis to one another. Draw the structure of this product, by completing the template structure below. (3)

O

CH

CH

1

3

4

1

3

4

.

22. [15] There are 4 parts to this question.

A) give the structures of F, G, H, J and K in the boxes provided below: (10)

OH

O

H KMnO₄

dilute HBr cool

Mg ether

i)

ii) dilute acid

CO₂

G

H

J

F

K

ii) What spectroscopic technique would you use to determine if an unknown sample contained compound F or compound J. (1)

iii) For the technique you chose, what are the differences that let you decide between F and J (1-2 sentences)? (2)

iv) What technique would you use to separate a mixture of compounds F and J into pure compounds? (1)

23. [15]

(A) Draw the MAJOR ORGANIC PRODUCT that is expected in each of the following four reactions with X. Use the space provided at the end of each arrow: (8)

OH Br

Elimination

X

1 eq. NaOH, S_N2

H₂SO₄ hot conc elimination 1 eq. HI,

S_N1

cold dilute 1 eq. NaOH,

hot conc

B) In the first step of the SN1 reaction, compound X becomes protonated. Draw a

mechanism for this process using curly arrows showing all lone pairs and charges. (2)

C) Provide a mechanism for the second step of the SN1 reaction (using curly arrows

showing all lone pairs and charges) (2)

D) Provide a mechanism for the third step of the SN1 reaction (using curly arrows

24. [15] Starting from compound C, a research student performed a series of reactions to prepare compound A (formula C7H12). Unfortunately, a constitutional

isomer was also produced B. The IR, 1H NMR and 13C NMR are provided for compounds A and B.

dilute acid

CONC HOT H₂SO₄ OLi

C D

A B

i) fill in the intermediate in the box shown (D) (2) ii) Will the equilibrium favour C or D? (1)

iii) WHY (one sentence)? (2)

v) The spectra for compound B are found on the next page. Draw the structure of B in the box above. Explain how the spectra provided are consistent with the structure of B you chose (1 sentence each for IR, 1H NMR, 13C NMR) (5)

vi) BONUS QUESTION: Which will be formed in higher yield A or B and WHY?

DATA FOR A

1_{H NMR} 13_{C NMR}

1H 4H

3H 4H

2 lines

+ total 5 lines

DATA FOR B

1_{H NMR} 13_{C NMR}

2H 4H 6H + total 3 lines

2 lines

Mini-Periodic Table

Approx. atomic masses for some atoms given in parentheses.

H(1) He(4)

Li(7) Be(9) B(11) C(12) N(14) O(16) F(19) Ne(20) Na Mg Al Si P(31) S(32) Cl(35.5) Ar

K Ca Ga Ge As Se Br(80) Kr

I(127)

Acid pK_a

HI

HBr

HCl

H₂SO₄

H₃O+

H₃PO₄ CH₃CO₂H H₂CO₃ NH₄+

HCO₃

-H₂O

CH₃CH₂OH

CH₃C=OMe HC CH H₂

NH₃

CH₂=CH₂

CH₃CH₃

-9 -8 -7 -5.2 2.1 9.24 10.33 15.9 20 38 -1.74 25 35 4.76 6.36 15.7 44 51

Coupling constants, J (Hz) 1-bond: >30

2-bond: 16

IR correlation chart: