SYSTEMWIDE CHEM 2425 FINAL EXAM. Department Of Physical Sciences

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1 SYSTEMWIDE CHEM 2425 FINAL EXAM Department f Physical Sciences Morphine NAME:

2 RGANIC CHEM 2425 FINAL EXAM DIRECTINS- A periodic table is attached at the end of this exam. Please answer all questions in the space provided as completely and clearly as possible. Please show all your work for the writing portions of the exam. PART I- Multiple Choice ( 2 points each) 1. How many signals are present in the proton NMR of the compound shown? (neglect signal splitting). A. 1 B. 2 C. 3 D A compound having the formula C 7 H 8 gave the following proton NMR spectrum data: (7.28, multiplet, 5H) ( 4.58, singlet, 2H) (2.43, singlet, 1H) - CH 2 H H CHH. 3. Which of the following is aromatic? 2

3 4. What dienophile is used to synthesize the compound shown? C 2 C 2 C 2 - C C - C 2 C 2 - C H = C H- C 2 C 2 C 2 C 2 C 2 5. Which of the following is an enol? H H H 6. What functional group does the following molecule contain? H A. lactone B. hemiacetal C. acetal D. lactam 7. Which of these is an ortho- para director? A. N 2 B. CH 2 C. C-NH 2 D. C-CH 2-8. The nitration of benzaldehyde yields predominantly: A. o nitrobenzaldehyde B. p nitrobenzaldehyde C. m nitrobenzaldehyde D. a mixture of both A and B 3

4 9. Which of the following compounds is the strongest acid? CH CH CH CH Br N Which of the following is a tertiary amine? A. CH 2 NHCH 2 B. CH 2 NH 2 C. ( CH 2 ) 2 NCH 2 D. ( CH 2 ) 4 N Which of the following reagent when added to benzene and bromine lead to bromobenzene? A. NaCl B. NaBr C. FeBr 3 D. NaH 12. What is the IUPAC name of the compound shown? NH 2 A. 1-chloro-2-bromo-4-anisole B. 3-bromo-4-chloroanisole C. 1-bromo-2- chloro-5-aniline D. 3-bromo-4-chloroaniline 13. Which of the following is the structure of phthalic anhydride? Cl Br 4

5 14. Which of the following compound is the most reactive toward Br 2 /FeBr 3? CH N Carboxylic acids have higher boiling points than ethers of similar molecular weights. Which of the following best explains this observation? A. strong C polarity B. hydrogen bonding C. strong H polarity D. all of these 16. Which of the following is most acidic? A. CHCl CH B. FCH 2 CH 2 CH C. CH 2 CH D. BrCH 2 CHF CH 17. Which of the following statements about pyridine (structure shown below) is not true? A. pyridine is an aromatic compound. N B. All of the atoms that make up the pyridine molecule lie in the same plane. C. Pyridine is a weak base because it would become non-aromatic if it accepted a proton. D. Pyridine has a cyclic pi system. 18. In, the sample is irritated with radio waves in the presence of a magnetic field. A. infrared spectroscopy B. nuclear magnetic resonance spectroscopy C. mass spectroscopy D. none of these 19. Which of the following compounds will have an absorption at cm -1 in its infrared spectrum? A. CH 2 B. CH 2 CH 2 C C. CH 2 N 2 D. CH 2 CH 2 CH 2 H 5

6 20. How many types of hydrogens (sets of signals) would you expect to observe in the 1 H NMR spectra for the following compound? A. 1 B. 2 C. 3 D. 4 PART II. Nomenclature and structures (3 points each) 21. Give the correct structures for the following names: a) m-nitrobenzaldehyde b) 3- bromo- 4-chloro-1- methoxybenzene c) N- methylaniline 22. Give the correct IUPAC names for the following structures: S 3 H Br Cl (a) (b) ( c) a) b) c) 6

7 PART III. Synthesis ( 4 points each ) 23. Show by a series of reactions how you could prepare the following compounds from the indicated starting compound. Be sure to clearly indicate the reagents used in each step. a) CH 2 CH CH 2 CH 2 CH b) CHBr - NH 2 7

8 PART IV. Reactions ( 2 points each ) 24. Give the major organic product(s) of each of the following reactions. Please show all relevant stereochemistry. H - a) b) CH 2 CH Cl H 2 (aldol condensation) NaNH 2 NH 3 c) HN 3 H 2 S 4 C d) CCl 1) NH 3 2) LiAlH 4 e) CH + NH 2 f) + HBr 80 o C g) N 2 + Cl - H CuCl HCl h) NaH CH 2 Br i) + 8

9 J) NH 3 warm PART V. Mechanisms (4 points each ) 25. For the following reaction, write a complete mechanism for reaction which adequately accounts for the formation of product. Show all intermediate structures and all electron flow using the curved arrow convention. a) H - H b) Cl 2 / FeCl 3 Cl 9

10 PART VI. Spectroscopy problems (3 points each) 26. a) Compound X has the molecular formula C 10 H 12. The IR spectrum of X has a strong band near 1710 cm -1. Compound X forms a phenylhydrazone, but gives a negative Tollens test and a positive iodoform test. What is a possible structure of compound X? b) Suggest a structure that is consistent with all the spectral data given below. (C 7 H 14 ) 10

11 RGANIC CHEM 2425 FINAL EXAM ANSWERS FALL 2005 PART I.- Multiple Choice (2 points each) 1. B 2. B 3. D 4. A 5. D 6. B 7.B 8. C 9. B 10. C 11. C 12. D 13. C 14. B 15.D 16. D 17. C 18. B 19. D 20. D PART II Nomenclature and structures ( 3 points each) 21. CH a) b) c) NH - N 2 Cl Br 22. a) 5-Bromo-1,3-pentadiene b) 3-Hydroxy-4-penten-2-one c) 3-Chlorobenzenesulfonic acid (or / m- Chlorobenzenesulfonic acid). PART III : Synthesis ( 4 points each) 23. a) CH 2 CH CH 2 CH 2 CH H 3 + / heat 1) LiAlH 4 2) H 3 + CH 2 CH 2 H PBr 3 CH 2 CH 2 Br NaCN CH 2 CH 2 CN 11

12 b) CHBr - NH 2 Cl AlCl 3 LiAlH 4 H 3 + / heat Br 2 / light CH 2 Br NaCN CH 2 CN PART IV. Reactions ( 2 points each) 24. a) H b) NH 2 c) NH2 d) CH 2 NH2 e) N - - C - H f) Br g) Cl C h) CH 2 i) J) H 2 N - C - CH = CH - C -H PART V. Mechanisms (4 points each) 25. a) - :.. H - CH : H b) FeCl 3 + Cl -Cl [ FeCl 4 ] :Cl.. + H.... :Cl.. + Cl:.... Cl - : Cl.. - FeCl 3 12

13 PART VI. Spectroscopy problems (3 points each) 26. (a) DU = (10) (12/2) +1 = 5 degree of unsaturation, consists of benzene ring. C - CH 2 b) DU = (7) (14/2) +1 = 1 degree of unsaturation, consists of one double bond. - C - CH 2 - CH 2 - CH 2 - CH 2-13