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96年 - 96學士後西醫-有機化學 #37201

科目：學士後西醫-有機化學 | 年份：96年 | 選擇題數：80 | 申論題數：0

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所屬科目：學士後西醫-有機化學

選擇題 (80)

1. The Keq for the interconversion for the two chair forms of methylcyclohexane at 25 °C is 18. What % of the chair conformations feature an axial methyl group? (A) 95 (B) 75 (C) 50 (D) 25 (E) 5
2. What is the name of the major organic product of the following reaction?  (A) 3,3-dimethyl-1-butanol (B) 3,3-dimethyl-2-butanol (C) 2,3-dimethyl-2-butanol (D) 2,3-dimethyl-1-butanol (E) 4-methyl-2-petanol
3. How many diastereomer(s) exist for the compound below? 
 (A) 2 (B) 4 (C) 6 (D) 8 (E) 0
4. Which of the following statements is (are) true for the Diels-Alder reaction? (A) When the diene is electron-rich, the reaction works best when the dienophile contains one or more electron-withdrawing groups conjugated to its C=C. (B) Substituents which are cis in the dienophile remain cis in the product. (C) Dienes which cannot achieve an s-cis conformation do not react in Diels-Alder reactions. (D) Secondary orbital interactions typically cause the endo product to be favored kinetically over the exo. (E) All of the above.
5. What is the major product of the following reaction?
6. Which sequence of reagents works best to convert 3-hexene to 3-hexyne? (A) 1. HCl 2. NaNH2 (B) 1. BH3．THF 2. HO- , H2O2 3. NaNH2 (C) 1. NaNH2 2. HI 3. H3O+ (D) 1. Br2, CH2Cl2 2. NaNH2 (excess) (E) 1. Cl2, CH2Cl2 2. NaCN(excess)
7. Which of the following technique(s) can readily distinguish between:
 (A) NMR (B) IR (C) MS (D) A and B (E) A and C
8. What is the major product of the following reaction?
9. What is the major product of the following reaction?
10. What is the major product from the following rearrangement?
11. At what position of the pyridine ring in the coenzyme below will oxidation-reduction reaction take place? 
 (A) 1 (B) 2 (C) 3 (D) 4 (E) 5
12. Which of the following reaction is called Knoevenagel reaction? 

13. Which of the following structures is a Fischer projection of (2R,3R,4S)-2,3,4-tribromoheptane?(A)(B)(C)(D)(E) None of the above
14. Arrange the following substrates in order of their increasing SN2 reactivity with NaCN: (I) 1-bromopentane, (II) 1-chloro-2,2-dimethylpentane, (III) 2-bromo-2-methylpentane, and (IV) 1-chloro-3,3-dimethylpentane. (A) IV < II < I < III (B) III < I < IV < II (C) IV < II < III < I (D) III < II < IV < I (E) None of the above
15. Both [E]- and (Z)-hex-3-ene can be treated with D2 in the presence of a platinum catalyst. How are the products from these two reactions related to each other? (A) The [E]- and (Z)-isomers generate the same products but in differing amounts. (B) The [E]- and (Z)-isomers generate the same products in exactly the same amounts. (C) The products of the two isomers are related as constitutional isomers. (D) The products of the two isomers are related as diastereomers. (E) The products of the two isomers are related as enantiomers.
16. Consider the data illustrated below. The formula of unknown compound is C9H9N IR (cm-1): 3050, 2950, 2240, 1630 1H NMR (δ): 7.5 (2H, d), 7.1 (2H, d), 2.3 (2H, q), 0.9 (3H, t) 13C NMR (δ): 137 (s), 130, (s), 126 (d), 122 (d), 95 (s), 25 (t), 15 (q) The structure of unknown compound is? (A)(B)(C)(D)(E)
17. In electrophilic aromatic substitution reactions, the hydroxyl group is an o,p-director because: (A) it donates electron density to the ring by induction and destabilizes the meta sigma complex. (B) it donates electron density to the ring by induction and stabilizes the ortho and para sigma complexes. (C) it donates electron density to the ring by resonance and destabilizes the meta sigma complex. (D) it donates electron density to the ring by resonance and stabilizes the ortho and para sigma complexes. (E) None of the above.
18. (S)-2-Methylbutanal __________ upon sitting in an acidic or a basic aqueous solution. (A) racemizes (B) esterifies (C) inverts completely to the R configuration (D) hydrolyzes (E) irreversibly forms the hydrate
19. When a carbonyl is part of a conjugated π-network, the C=O stretch: (A) has a higher frequency than in a nonconjugated system. (B) has a lower frequency than in a nonconjugated system. (C) always occurs at 1710 cm-1 . (D) occurs around 2700 cm-1 . (E) cannot be distinguished from the C=O stretch in a nonconjugated system.
20. When pent-1-ene is treated with mercury(II) acetate in methanol and the resulting product is reacted with NaBH4, what is the primary organic compound which results? (A) 3-ethoxypentane (B) 1-methoxypentane (C) 1-ethoxypentane (D) 2-ethoxypentane (E) 2-methoxypentane
21. What is the major product of the following reaction? 
(A) I (B) II (C) III (D) IV (E) None of the above.
22. Which of the following terms describes the mechanism of a Claisen rearrangement reaction? (A) Electrophilic addition (B) Nucleophilic addition (C) syn Elimination (D) Radical substitution (E) Pericyclic reaction
23. What is the major organic product obtained from the following reaction?
 (A) 1 (B) 2 (C) 3 (D) 4 (E) 5
24. What is the major organic product obtained from the following sequence of reactions? 
 (A) 1 (B) 2 (C) 3 (D) 4 (E) 5
25. What is the major product of the following reaction? 
(A) 1 (B) 2 (C) 3 (D) 4 (E) 5
26. Which of the following terms best describes the compound shown below?
 (A) a lecithin (B) a diterpene (C) a steroid (D) a glyceride (E) a prostaglandin
27. What configurations are found in the product(s) of the reaction shown below?
 (A) 1R, 2R only (B) 1S, 2S only (C) 1R, 2S only (D) An equal mixture of 1R, 2R and 1S, 2S (E) An equal mixture of 1R, 2R and 1R, 2S
28. Which of the following statements correctly describes the molecule shown below? 
 (A) It is achiral (B) It is meso (C) Its asymmetric center possesses the R configuration (D) The mirror image of this molecular is its enantiomer (E) The molecule possesses enantiotopic hydrogens
29. Which of the following m/z values is the base peak for benzyl alcohol? (A) 17 (B) 52 (C) 77 (D) 91 (E) 108
30. What splitting pattern is observed in the proton NMR spectrum for the indicated hydrogens?
 (A) Singlet (B) Doublet (C) Triplet (D) Singlet of singlet (E) Multiplet
31. The Hell-Volhard-Zelinsky reaction involves: (A) α-Bromination of carboxylic acids (B) α-Bromination of ketones (C) Formation of α, β -unsaturated carboxylic acids (D) Formation of β-ketoesters (E) Formation of amines
32. Which of the following reagents would reduce carboxylic acids and esters into alcohols? (A) H2/Ranney Ni (B) 1) LiAlH4; 2) H3O+ (C) 1) NaBH4; 2) H3O+ (D) Na/NH3 (E) Zn(Hg)/H+
33. Which of the following reducing agents is best used in the reaction shown below?
 (A) H2/Ranney Ni (B) 1) LiAlH4; 2) H3O+ (C) 1) NaBH4; 2) H3O+ (D) Na/NH3 (E) Zn(Hg)/H+
34. What is the systemic name of the following compound?
 (A) 1-Azabicyclo[2,2,1]heptane (B) 2-Azabicyclo[2,2,1]heptane (C) 1-Azabicyclo[2,2,1]hexane (D) 2-Azabicyclo[2,2,1]hexane (E) 1-Azabicyclo[2,1,1]hexane
35. What is the name of the following reaction?
 (A) Wittig reaction (B) Michael reaction (C) Dieckmann condensation (D) Cope reaction (E) Knoevenagel reaction
36. Which of the following lists the correct order of reactivity of the substrates in electrophilic aromatic substitution reactions? (A) Thiophene > pyrrole > furan > benzene (B) Benzene > thiophene > furan > pyrrole (C) Furan > pyrrole > benzene > thiophene (D) Pyrrole > furan > thiophene > benzene (E) Benzene > furan > pyrrole > thiophene
37. In the addition of HBr to alkynes in the absence of peroxides, which of the following species is believed to be an intermediate? (A) Vinyl anion (B) Vinyl cation (C) Vinyl radical (D) Carbene (E) Bromonium ion
38. Which of the following statements about propene is correct? (A) All of the hydrogen atoms are in the same plane (B) The compound has a cis and trans isomer (C) It generally acts as a Lewis acid (D) There is a total of eight sigma bonds (E) All the carbon atoms are sp2 hybridized
39. The t-butoxycarbonyl group (Boc) is a widely used protecting group for primary amine and secondary amine. What reagent is commonly used for deprotection of N-Boc group in the Merrifield solid phase peptide synthesis? (A) OH- (B) Pd/C, H2 (C) Pd(OH)2/C, H2 (D) Acetic acid (E) CF3COOH
40. Predict the product of the following reaction:
(A)(B)(C)(D)(E) None of the above
41. The best method for preparation nonhalogenated cyclopropanes is by a process called the _________ reaction. (A) Claisen rearrangement (B) Schmidt (C) Curtius (D) Pauson-Khand (E) Simmon-Smith
42. In the following structures, the general structure of sulfone is _________. 
(A) A (B) B (C) C (D) D (E) E
43. What is the major organic product of the following sequence of reactions?
44. Choose the best reagent for carrying out the following conversion.
 (A) 1. PhMgBr, ether; 2. H3O+ (B) 1. PhCH2MgBr, ether; 2. H3O+ (C) (C6H5)3P=CHC6H5, THF (D) Li(C6H5)2Cu, ether (E) None of the above
45. From the structures (I-IV) giving below which one belongs to nucleotide.
 (A) I (B) II (C) III (D) IV (E) None of the above
46. What fragment ion (m/z) is produced from McLafferty rearrangement of 5-methyl-2-hexanone in EI-MS? (A) 114 (B) 43 (C) 58 (D) 108 (E) None of the above
47. Select the most reasonable formula for the compounds with the following mass spectral data: M+ at m/z = 136 and M+2 at m/z = 138 of approximately equal intensity. (A) C6H13OCl (B) C4H9Br (C) C10H16 (D) C9H12O (E) None of the above
48. If a compound has the –OH, –OCH3, and –CHO groups all attached to a single benzene ring, the IUPAC name of the compound is based on which of the following? (A) Anisole (B) Benzaldehyde (C) Phenol (D) Methylether (E) Phenyl
49. Which one of the following would NOT be a suitable solvent for Grignard reagents? (A) Diethyl ether (B) Tetrahydrofuran (THF) (C) Ethanol (D) Hexane (E) They would all be suitable solvents
50. (S) (+)-Butanol shows a specific rotation at +13.52o . What is the ratio of (S) (+)-butanol and (R) (-)-butanol when the measured rotation equals to +6.76o ? (A) (S) : (R) = 4 : 1 (B) (S) : (R) = 2 : 1 (C) (S) : (R) = 1 : 2 (D) (S) : (R) = 1 : 2.5 (E) (S) : (R) = 3 : 1
51. Consider the SN1 reaction of tert-butyl chloride with iodide ion: (CH3)3C-Cl + I - → (CH3)3C-I + Cl- If the concentration of iodide ion is doubled, the rate of forming tert-butyl iodide will: (A) Double (B) Increase 4 times (C) Remain the same (D) Decrease (E) Triple
52. Which of the following functional groups would NOT show an IR absorbance above 3000 cm-1? (A) An amine (NH2) (B) A carbonyl (C=O) (C) An alcohol (OH) (D) A vinylic carbon-hydrogen bond (=C-H) (E) A methylene hydrogen (-CH2-)
53. Which part of the electromagnetic spectrum interacts with the nuclear spins of protons ? (A) Radio Waves (B) X-Ray radiation (C) Visible Light (D) Infrared radiation (E) Ultra violet light
54. The pinacol rearrangement proceeds via intermediate. (A) carbanion (B) carbocation (C) radical (D) carbene (E) neutral
55. Which carbon in the following sugar is the anomeric carbon atom?
 (A) a (B) b (C) c (D) d (E) e
56. A tree diagram for the splitting of a proton Ha is reproduced below. What is the origin of this splitting pattern? 
(A) Ha is coupled to two nonequivalent hydrogens with identical coupling constants. (B) Ha is coupled to two nonequivalent hydrogens with different coupling constants. (C) Ha is coupled to three nonequivalent hydrogens with identical coupling constants. (D) Ha is coupled to three nonequivalent hydrogens with different coupling constants. (E) Ha is coupled to three equivalent hydrogens with identical coupling constants.
57. Which of the following combinations of reactants would produce a meso compound? (A) Cis-3-hexene and Br2 (B) Trans-3-hexene and Br2 (C) Cis-3-hexene and Br2 in H2O (D) Trans-3-hexene and Br2 in H2O (E) Trans-3-hexene and H2/Pd/C
58. What is the product of the following sequence of reactions?
 (A) 1,1-Diethylcyclopropane (B) Cis-1,2-diethylcyclopropane (C) Trans-1,2-diethylcyclopropane (D) Cis and trans-1,1-diiodo-2,3-diethylcyclopropane (E) Cis-1,2-diethyl-3,3-diiodocyclopropane
59. An unknown hydrocarbon shows a parent peak on the mass spectra at m/z = 86. There is no evidence of absorption from visible or UV spectra. The IR shows no major absorption outside the C-H stretch and bending vibration. The 1 H NMR reveals a singlet at δ 0.9 (9H), a triplet at 0.98 (3H) and a quartet at 1.6 (2H). Which compound below best fits the description? 
60. Which statement is correct for the reaction shown below? 1-chloro-2,4-dinitrobenzene + NaOH → 2,4-dinitrophenol (A) This reaction is an electrophilic aromatic substitution. (B) This reaction is a SN1 substitution. (C) This reaction is a nucleophilic aromatic substitution. (D) Substituted benzyne is the reaction intermediate. (E) None of the above. II. Choose one correct answer for the following questions 
【單選題】每題 2 分，共計 40 分，答錯一題倒扣 0.5 分，倒扣至本大題零分為止，未作答，不給分亦不扣分。

61. What is the product of the following reaction?
62. What is the major product of the following reaction?
63. What is the major product of the following reaction?

64. Which of the following compounds is the major organic product generated in the reaction below? Pay particular attention to region- and stereochemical detail. 

(A)(B)(C)(D)(E) None of the above.

65. Which of the following series of synthetic steps could be used to carry out the transformation shown below?
 (I) NaOH, (II) HCl, (III) PCC, (IV) O3, (V) S(CH3)2, (VI) H2O2, NaOH (A) II → IV → V (B) III → V → I (C) IV → VI → III (D) IV → V → I (E) None of the above.
66. What is the major organic product obtained from the following reaction?
 (A) 1 (B) 2 (C) 3 (D) 4 (E) 5
67. Which of the following statements correctly describes the molecule shown below? 
 (A) Its C-4 NH2 is strongly basic while the C-1 NH2 is weekly acidic. (B) Its C-4 NH2 is weekly basic while the C-1 NH2 is strongly acidic. (C) Its C-4 NH2 is weekly basic while the C-1 NH2 is weekly acidic. (D) Its C-4 NH2 is strongly basic while the C-1 NH2 is strongly acidic. (E) Both C-1 NH2 and the C-4 NH2 are weekly basic.
68. Which of the compounds below undergoes solvolysis in aqueous ethanol most rapidly? (A) Cyclohexyl bromide (B) Isopropyl chloride (C) Methyl iodide (D) 3-Chloropentane (E) 3-Iodo-3-methyl pentane
69. Which of the following E, Z designation are incorrect?
 (A) AB (B) BC (C) CD (D) AD (E) AC
70. Provide structure for compound A in the following reaction scheme:   (A) A (B) B (C) C (D) D(E) None of the above
71. What is the major organic product of the following sequence of reactions?  
72. What product would you obtain from Claisen condensation of ethyl propanoate? (A) Ethyl 2-ethyl-3-oxopentanoate (B) Propyl 2-methyl-3-oxopentanoate (C) Ethyl 2-methyl-3-oxohexanoate (D) Propyl 2-methyl-3-oxohexanoate (E) Ethyl 2-methyl-3-oxopentanoate
73.What is the major organic product of the reaction shown below?
 (A) Ethyl benzoate (B) Phenyl propionate (C) Diphenyl ketone (D) Phenyl vinyl ketone (E) An phenylseleno ketone
74. Which of the following reactions has a mechanism that involves the formation of a cyclic intermediate from acyclic starting materials? (A) Dehydration of an alcohol (B) Addition of HBr to an alkene (C) Chlorination of an alkane (D) Addition of bromine to an alkene (E) Addition of Grignard to ketone
75. Which of the following substituents would have the lowest Cahn-Ingold-Prelog priority? (A) -CH2OH (B) -CH2COOH (C) -CH2CH2Cl (D) -CH2NH2 (E) -CH2CH2Br
76. Which sets of reagents would give the correct product for this reaction?
 (A) Hg(OCOCF3)2 in MeOH (B) 1. Hg(OAc)2 in THF/H2O2, 2. NaBH4 (C) 1. BH3, 2. NaOH, H2O2 (D) 1. BH3, 2. H2O2, OH- , 3. NaH, 4. CH3I (E) H+ , CH3OH
77. The Frost circle can be used to reproduce the molecular orbital energies of a cyclic polyene. What species would be described by the Frost circle to the right?
 (A) Cyclopentadienyl cation (B) Cyclopentadienyl radical (C) Cylopentadienyl anion (D) Cyclopentadiene (E) Cyclopentene anion
78. What is the product of acid-catalyzed hydrolysis of the ketal shown below? ？ 
79. What is the product in the following reaction sequence?
(A)(B)(C)(D)(E)  None of the above
80. What is the major product for the following reaction?

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