Organic Chemistry II A KEY February 24, 2011

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1 rganic Chemistry II A KEY ebruary 24, 2011 Exam 1: VERI A 1. Which of the following reagent(s) (or set of reagents) could react with atorvastatin (LIPITR) as starting material? D or E Atvorvastatin (LIPITR) C 2 Reagents I. Br 2, ebr 3 II. 1) a 2 2) Br 3, 2 4 IV. Br b) I & II c) III & IV d) I, II & III e) I, II, III & IV 2. Rank the following compounds from most acidic to least acidic. (Use the A phenol for structure III) I. II. C 3 o correct answer given III > I > IV > II 2 Triclosan IV. Eugenol > II > III > IV b) IV > II > I > III c) III > I > II = IV d) III > IV > I > II e) II = IV > I > III A B Tolcapone Albuterol 3. ow many π electrons are associated with the aromatic system in the compound below? B a) 2 b) 6 c) 10 d) 14 e) The compound is not aromatic 1

2 rganic Chemistry II A KEY ebruary 24, 2011 Exam 1: VERI A 4. There are six nitrogen atoms labeled in the structure of abacavir (ZIAGE) below. Which of these nitrogen atoms is the least basic? D Abacavir (ZIAGE) 3 4 a) 1 & 6 b) 2 & 4 c) 2 d) 4 e) 3 & 5 5. Which of the following statements most accurately describes the structure below? B C lecainide (TAMBCR) a) The compound contains two ionizable functional groups. b) The highlighted ring contains two activating and one deactivating group. c) The compound contains one para substituted ring. d) Reaction of this compound with 2, e 3 will occur at C 2 to give one of the major products of the reaction. e) b & c C 3 6. Which of the criteria for aromaticity is met for the compound given below? E I. Cyclic II. Planar Continuous π system IV. n= integer in uckel rule b) I & II c) I, II & III d) I, II, & IV e) I, II, III & IV 7. Which of the following statements is true regarding the reaction given below? D 3 P 4 I. Two positional isomers form in the reaction II. The major product of the reaction is aromatic The reaction involves a 1,2 hydride shift IV. The reaction occurs through an 1 mechanism. b) II c) II & III d) III e) I, III & IV 2

3 rganic Chemistry II A KEY ebruary 24, 2011 Exam 1: VERI A 8. Which hydrogen atom in the compound below has the lowest pka? A d c b a) a b) b c) c d) d e) All have approximately the same pka. a 9. The major product(s) of the reaction will have a nitro group at the position(s) in the reaction outlined below. C I. C 3 II. C 4 C 5 IV. C 6 & III b) II c) II & IV d) III e) I, II, III & IV 10. Which of the following compounds is aromatic? B I. II. IV. b) I & II c) II & III d) II e) III & IV 11. Three pkbs corresponding to three substituted anilines are given in the table below. Assign each pkb to its proper substituted aniline. D pkbs C 2 2 I II III C = 9.77 ; II =11.83; III = b) I = ; II =11.83; III = 9.77 c) I = ; II =13.26; III = 9.77 d) I = ; II =9.77; III = e) I = ; II =9.77; III =

4 rganic Chemistry II A KEY ebruary 24, 2011 Exam 1: VERI A 12. Which of the following structures represents a reaction intermediate that is generate upon reaction of ortho fluoronitrobenzene with C 3 a +? D a) b) C 3 3 C c) d) 3 C 3 C e) one of these 13. tarting with benzene, which sequence of reagents could be used to best prepare 1 bromo 4 isopropyl 3 nitrobenzene? (ote: ther isomers may also form) B or C a) 1. Br 2, ebr , isopropyl chloride, Al 3 b) 1. isopropyl chloride, Al , Br 2, ebr 3 c) 1. isopropyl chloride, Al 3 2. Br 2, ebr , 2 4 d) 1. 3, Br 2, ebr 3 3. isopropyl chloride, Al 3 e) 1. 3, isopropyl chloride, Al 3 3. Br 2, ebr Rank the relative rates of formation of products from fastest to slowest (fastest>slowest) in the series of reactions below. D I. 1. 2, e 3 II. 2. 3, , Al , 2 4 > II > III b) III > II > I c) II > III > I d) II > I > III e) III > I > II 1., Al , 2 4 4

5 rganic Chemistry II A KEY ebruary 24, Reaction of 1 fluoro 2,5 dimethylbenzene with 1. a 2. Br will result in: D a) a 50:50 mixture of two positional isomers as products b) a 25:25:25:25 mixture of four positional isomers as products c) a 25:25:50 mixture of three positional isomers as products d) only one product e) no reaction Exam 1: VERI A 16. Match each compound (A D) with its reaction chemistry in electrophilic aromatic substitutions (EA) and nucleophilic aromatic substitutions (A) (I IV). A I. Reacts in both EA and A II. Reacts in A but not EA Reacts in EA but not A IV. Does not react in either EA or A = A; II = B; III = C ; IV = D b) I = A; II = B; III = D; IV = C c) I = D; II = C; III = B; IV = A d) I = B; II = A; III = C; IV = D e) I = A; II = C; IV = B; IV = D A. B. C C C. D. 2 C 3 2 C 3 C Aromatic hydroxylation is a metabolic pathway that results in introducing a hydroxyl group onto the aromatic ring via a mechanism similar to the electrophilic aromatic substitution (EA). The specific position on the ring where aromatic hydroxylation occurs is generally influenced by the presence of substituents on the ring similar to substituent effects observed in the EA reaction. Based on this information, which of the following compounds would be predicted as the major hydroxylated metabolite(s) of mepivacaine (CARBCAIE), a local anesthetic? E a) b) Mepivacaine (CARBCAIE) c) d) e) a & c 5

6 rganic Chemistry II A KEY ebruary 24, 2011 Exam 1: VERI A 18. Rank the products of the reactions below from strongest acid to weakest acid (strongest > weakest). D I. II IV. Br II> I > II > IV b) IV > III > II > I c) III > II > IV > I d) III > II > I > IV e) IV > I > II > III C A resonance form of the compound below is: B 2 I. II. 2 2 b) II & III c) II d) II & IV e) III 2 IV Which of the following represents a reaction intermediate that would form in the chlorination reaction of 2 nitrotoluene to give the major product(s) of the reaction? C I. II. 2 C 3 2 IV. 2 C 3 2 b) II c) I & III d) IV e) II & IV C 3 C 3 6

7 rganic Chemistry II A KEY ebruary 24, 2011 Exam 1: VERI A 21. Which of the following reactions corresponds to the reaction energy diagram below? C T T T a) b) 3 P 4 3 P 4 EERGY T RI c) d) 3 P 4 3 P 4 RI e) a & c M P 2 P 1 REACTI PRGRE 22. Which of the following represents a conjugate base of paraflutizide? B 2 Paraflutizide I. II. 3 2 b) II c) II & III d) I & IV e) III 2 IV The major product(s) that would form in the monoalkylation reaction of meta dimethoxybenzene, tert butyl alcohol and acetic acid is (are): A I. 1 tert butyl 2,4 dimethoxybenzene II. 5 tert butyl 1,3 dimethoxybenzene 4 tert butyl 1,2 dimethoxybenzene IV. 2 tert butyl 1,3 dimethoxybenzene V. 3 tert butyl 1,2 dimethoxybenzene b) I & II c) III & V d) IV &V e) V 7

8 rganic Chemistry II A KEY ebruary 24, 2011 Exam 1: VERI A 24. The pka values of benzoic acid and hydroxysubstituted benzoic acids have been determined experimentally and are provided below. Based on these pka values (not sigma values), which of the following statements is most consistent with this data? D Acid pka Benzoic acid 4.19 o ydroxybenzoic acid 2.98 m ydroxybenzoic acid 4.08 p ydroxybenzoic acid 4.58 a) ydroxy substituents follow a resonance effect, regardless of its position on the ring. b) ydroxy substituents follow an inductive effect regardless of its position on the ring c) ydroxy substituents follow an inductive effect in the meta position and a resonance effect in the ortho and para positions. d) ydroxy substituents follow an inductive effect in the ortho and meta positions and the resonance effect in the para position e) ydroxy substituents follow an inductive effect in the ortho position and a resonance effect in the meta and para positions. 25. Which of the following reagents could be used in the reaction outlined below? E a) b), Al 3, Al 3 c) d), Al 3, Al 3 e) a & b 8

9 rganic Chemistry II A KEY ebruary 24, 2011 Exam 1: VERI A ubstituent Abbreviation σ meta σpara acetamido Ac acetoxy Ac acetyl Ac alkenyl C 2 =C amino bromo Br tert butyl (C 3 ) 3 C chloro cyano C ethoxy Et ethyl Et fluoro hydrogen hydroxy methoxy Me methyl Me nitro phenoxy Ph phenyl Ph trifluoromethyl 3 C trimethylamino (C 3 ) Table 1: σ values for Various ubstituents 9

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