1. Which of the following pairs of compounds represent conformational isomers? NH 2 F OH

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1 rganic hemistry I Fall 2002 Exam 2 ovember 8, Which of the following pairs of compounds represent conformational isomers? a) b) c) d) e) b & c 2. Which of the following statements is true about ciprofloxacin, an antibiotic? F A Diamino-six membered ring a) The weakest base will be more ionized in the stomach (p ~2) than in the intestine (p ~4) b) There is no torsional strain energy associated with ciprofloxacin c) oth chair conformations of the diamino-six-membered ring have the same energy d) The most acidic functional group will be ~100% ionized in the stomach. e) a & c

2 rganic hemistry I Fall 2002 Exam 2 ovember 8, E 3. Unlike acetylcholine, only the most stable conformer about the 2-3 bond of succinylcholine is pharmacologically active. Which of the following ewman projections represents the pharmacologically active conformer of succinylcholine chloride? a) b) c) d) 2 3 Succinylcholine - - e) 4. The order, from most angle strain to least angle strain for the compounds below is: I II III IV a) I>II>III>IV b) III>I>IV>II c) III>I=IV>II d) II>IV=I>III e) IV>III>II>I 5. Which of the following structures corresponds to trans-1-chloro-4-methylcyclohexane? D a) b) c) d) e) 3 3 c & d 3 3

3 rganic hemistry I Fall 2002 Exam 2 ovember 8, Pyrole has a pka of 12. The pka of pyrole could be lowered the most by: A Pyrole 2 a) a nitro group on the #3 carbon. b) a methyl group on the #3 carbon c) a hydroxy group on the # 2 carbon d) a methyl group on the #4 carbon e) none of these would influence the pka 7. Which of the following processes are exothermic? a) 3 3 b) R D c) d) 3 3 e) 3 3 a & c A 8. The correct IUPA name of the structure given is: a) trans-1-chloro-4-ethylcycloheptane b) trans-1-ethyl-4-chlorocycloheptane c) cis-1-chloro-4-ethylcycloheptane d) cis-1-methyl-4-chlorocyclooctane e) trans-1-chloro-3-ethylcycloheptane

4 rganic hemistry I Fall 2002 Exam 2 ovember 8, Timolol and lantanoprost are two agents used in the treatment of glaucoma, dispensed as eye drops. The p of the eye is ~7.4. Which of the following is true? pka = 9.2 pka = 7.4 E pka = 8.8 S pka = 8.9 Timolol Latanoprost a) Latanoprost is more readily absorbed than timolol. b) Timolol is more readily absorbed than latanoprost. c) Timolol is mostly (>50%) ionized in the eye d) Latanoprost has two ionizable functional groups. e) a & c 10. Which of the following statements is true for the reaction energy diagram given below? TS 4 E TS 1 RI 1 TS 2 RI 2 TS 3 P 1 a) onversion of starting material to product 1 is exothermic. b) The free energy ( G ) of the conversion of starting material to product 2 is zero. c) Product 1 and 2 are derived from different reaction intermediates d) The reaction is a two-step reaction e) b & c SM P 2 RX E 11. Which of the following statements is (are) true for ketoprofen? a) The Ka value is greater than 1 at a p of 2. b) Ketoprofen is more soluble in lipids at a p of 2 than at a p of 9. c) The conjugate base is more water soluble than the acid. d) a & b e) b & c ketoprofen

5 rganic hemistry I Fall 2002 Exam 2 ovember 8, Rotation around which bond of 2,3-dimethylbutane corresponds to the energy curve given below? Energy (kj) a) 1-2 b) 2-3 c) 3-4 d) a & c e) none of these Angle Torsional Strain Energy kj/mol kcal/mol Me Me-Me Steric Strain Energy Me-Me Me-Ethyl The most stable conformation of quinic acid is: 2 Quinic Acid a) b) 2 2 c) d) 2 2 e) one of these 14. The percent ionization of the carboxylic acid of lysergic acid at p = 8.1 is: D 3 Functional Group pka arboxylic acid 6.6 Amine (weak) 8.1 Amine (strong) 9.9 a) 85% b) 3% c) 32% d) 97% e) 15% Lysergic Acid

6 rganic hemistry I Fall 2002 Exam 2 ovember 8, The ionization scheme that most accurately describes what happens when cilastain is exposed to urine (p 5.6) is: R D 2 S ilastatin a) 2 S 2 S b) 2 S 2 S c) 2 S 2 S d) 2 S 3 S e0 2 S 2 S

7 rganic hemistry I Fall 2002 Exam 2 ovember 8, The reaction mechanism given below corresponds to which of the following reaction types? 3 - F 3 - a + F 3 3 F a) addition b) elimination c) substitution d) rearrangement e) radical 17. The order of pka values for the sulfonamide functional group from highest pka to lowest pka for the sulfa drugs given below is: A 3 S I 2 S II 2 a) I > II = III > IV b) IV > III > II > I c) IV > I > III > II d) II > IV > III > I e) I=II=III=IV 2 2 S S 3 2 III IV 18. Epoxides are 3-membered rings containing one oxygen atom with torsional strain energies and angle strain energies similar to cyclopropanes. ompound 1 is less stable than compound II but compound II is more stable than compound III. Which of the following statements is true regarding compounds I, II and III? D I II III 3 a) I has more torsional strain than II b) I & II have equal angle strain c) The angle strain energy of III is less than the total torsional strain energy and angle strain energy of II d) a & b e) a, b & c

8 rganic hemistry I Fall 2002 Exam 2 ovember 8, In the least stable conformation of cis-1-chloro-2-methylcyclohexane: a) both substituents are axial b) both substituents are equitorial c) the methyl is axial and the chloro is equitorial d) the chloro is axial and the methyl is equatorial Steric Strain Energies kcal -Me 1.0 kcal Me-Me 2.4 kcal Me- 1.9 kcal 20. Which of the following compounds is the weakest base? a) b) c) d) e) 21. Which of the following compounds will give a positive test result (cloudy or precipitate) with Ag 3 in ethanol? a) b) c) d) r e) none of these

9 rganic hemistry I Fall 2002 Exam 2 ovember 8, Which of the following reaction energy diagrams corresponds to the reaction given below? = hydride from a

10 rganic hemistry I Fall Exam 2 ovember 8, Which of the structural analogs of cholesterol given below could be distinguished from cholesterol with the 2 S 4 test? A 3 holestanol 7-holesten-3 ol 5,7-holestadien-3 ol holesterol a) 3 -cholestanol b) 7-cholesten-3 -ol c) 5,7-cholestandien-3 -ol d) b & c e) All of these structural analogs could be distinguished from cholesterol with the 2 S 4 test 24. In the reaction below r I- r- I a) I is the leaving group, r is the nucleophile and + is the electrophile b) r is the leaving group, I is the nucleophile and + is the electrophile c) + is the leaving group, I is the nucleophile, and r is the electrophile d) r is the leaving group, + is the nucleophile and I is the electrophile e) + is the leaving group, r is the nucleophile and I is the electrophile 25. A resonance form of the conjugate base of meta-nitrobenzoic acid is: a) b) D c) d) 2 m-nitrobenzoic acid e) b, c & d