Chapter SixteenMULTIPLE CHOICE QUESTIONS Topic: Nomenclature Section: 16.2 Difficulty Level: Easy 1. What is the correct IUPAC name for the following compound? A) B) C) D) E) Ans: O 2-Methyl-5-heptanone 7-Methyl-4-octanone 6-Isopropyl-4-octanone Isobutyl propyl ketone 1,1-Dimethyl-4-heptanone B Topic: Nomenclature Section: 16.2 Difficulty Level: Easy 2. What is the correct structure for 7-methyl-4-octanone? O I O II O O O V IV A) B) C) D) E) Ans: I II III IV V D 162 III Topic: Nomenclature Section: 16.2 Difficulty Level: Easy 3. What is the correct IUPAC name for the following compound? A) B) C) D) E) Ans: O 5,5-Dimethyl-2-heptanone 5-Ethyl-5,5-dimethyl-Methyl-2-octanone 5-Ethyl-5-methyl- 2-hexanone 5,5-Dimethyl-2-octanone 3,3-Dimethyl-6-heptanone A Topic: Nomenclature Section: 16.2 Difficulty Level: Easy 4. What is the correct structure for 5,5-dimethyl-2-heptanone? O O I O II O III H O V IV A) B) C) D) E) Ans: I II III IV V B 163 Topic: Nomenclature Section: 16.2 Difficulty Level: Easy 5. A correct name for the following compound would be which of those below? O H A) B) C) D) E) Ans: 2,5-Dimethyl-6-hexanal 2,5-Dimethylhexanal 2-Aldehydoisohexane 3,5-Dimethylheptanone 1-Hydro-2,5-dimethyl-1-hexanone B Topic: Nomenclature Section: 16.2 Difficulty Level: Easy 6. What is the correct structure for 2,5-dimethylhexanal? O O H I II III O O O H H IV A) B) C) D) E) Ans: V I II III IV V D 164 Topic: Nomenclature Section: 16.2 Difficulty Level: Medium 7. What is the correct IUPAC name for the following compound? O A) B) C) D) E) Ans: 5,5-Dimethyl-2-heptanone 5-Ethyl-5,5-dimethyl-Methyl-2-octanone 5,5-Dimethylcycloheptanone 4,4-Dimethylcycloheptanone 3,3-Dimethylcycloheptanone D Topic: Nomenclature Section: 16.2 Difficulty Level: Medium 8. What is the correct IUPAC name for the following compound? O A) B) C) D) E) Ans: 2,4-dimethyl-2-pentenone 2,5-dimethylcyclopenten-3-one 2,4-dimethylcyclopent-2-enone 3,5-dimethylcyclopent-2-enone 2-methyl-5-methylcyclopent-2-enone C 165 Topic: Nomenclature Section: 16.2 Difficulty Level: Medium 9. What is the correct IUPAC name for the following compound? A) B) C) D) E) Ans: O 1,1,2-Trimethyl-1,3-hexenone 1,2-Dimethyl-1,3-hexenone 2,3-Dimethyl-1,3-heptenone 2,3-Dimethyl-2-hepten-4-one 5,6-Dimethyl-5-hepten-4-one D Topic: Nomenclature Section: 16.2 Difficulty Level: Medium 10. What is the correct structure for 2,3-dimethyl-2-hepten-4-one? O I O II O III O IV O V A) B) C) D) E) Ans: I II III IV V E 166 Topic: Nomenclature Section: 16.2 Difficulty Level: Medium O 11. A correct name for C 6 H 5 C H 2 C H 2 C H is? A) 3-Benzylpropanone B) 3-Phenylpropanal C) 3-Benzylpropanal D) Nonanone E) Nonanal Ans: B Topic: Nomenclature Section: 16.2 Difficulty Level: Medium 12. What is the correct structure for 3-phenylpropanal? O O H O II I III O H O V IV A) B) C) D) E) Ans: I II III IV V E 167 Topic: Nomenclature Section: 16.2 Difficulty Level: Medium 13. What is the correct structure for 5-hydroxy-2-phenyl-3-hexanone? O Ph Ph OH Ph OH OH O III OH II I OH O O H IV A) B) C) D) E) Ans: V O I II III IV V C Topic: Nomenclature Section: 16.2 Difficulty Level: Medium 14. Which is the proper name for the structure shown? C H O C l C H A) B) C) D) E) Ans: 3 2-Chloro-5-aldehydotoluene 6-Chloro-3-aldehydotoluene 2-Methyl-4-aldehydochlorobenzene 4-Chloro-3-methylbenzaldehyde 4-Methyl-5-chloro-2-benzaldehyde D 168 Ph Ph Topic: Nomenclature Section: 16.2 Difficulty Level: Medium 15. What is the correct structure for 4-chloro-3-methylbenzaldehyde? O O H O H H Cl II I Cl Cl O H H O Cl Cl IV A) B) C) D) E) Ans: V I II III IV V A 169 III Topic: Nomenclature Section: 16.2 Difficulty Level: Medium 16. What is the correct structure for 3-methyl-5-(2,5-dinitrophenyl)pentanal? NO2 O O H O2N NO2 II I O NO2 NO2 O O2N H O2N H NO2 III IV O2N H O NO2 V A) B) C) D) E) Ans: I II III IV V B 170 Topic: Nomenclature Section: 16.2 Difficulty Level: Medium 17. What is the correct structure for 3-methyl-5-(4-chlorophenyl)hexanal? O O H Cl Cl I II O O H H Cl Cl IV III Cl O H V A) B) C) D) E) Ans: I II III IV V D 171 Topic: Nomenclature Section: 16.2 Difficulty Level: Medium 18. What is the correct structure for 7-bromo-1-octyn-4-one? Br Br Br O O O II I III Br Br IV A) B) C) D) E) Ans: O V O I II III IV V A Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 19. What is the correct IUPAC name for the following compound? Br A) B) C) D) E) Ans: O 2-Methyl-2-bromobutanone (S)-2-Bromo-2-methylcyclobutanone (R)-2-Bromo-2-methylcyclobutanone (S)-1-Bromo-1-methyl-2-cyclobutanone (R)-1-Bromo-1-methyl-2-cyclobutanone B 172 Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 20. What is the correct IUPAC name for the following compound? O Cl A) B) C) D) E) Ans: H (S)-3-chloro-1-hexanone (S)-1-chloro-3-hexanone (R)-3-chlorocyclohexanone (S)-3-chlorocyclohexanone (S)-1-chloro-3-cyclohexanone D Topic: Nomenclature Section: 16.2 Difficulty Level: Hard O 21. C H 3 C H C H 2 O H What is the IUPAC name for A) 4-Oxo-5-phenyl-2-hexanol B) 5-Hydroxy-2-phenyl-3-hexanone C) 2-Hydroxy-5-phenyl-4-hexanone D) 2-Hydroxypropyl-1-phenylethyl ketone E) 5-Hydroxy-3-keto-2-phenylhexane Ans: B 173 C C H C 6H C H 5 3 ? Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 22. Which is the proper name for the structure shown? O2 N O NO2 A) B) C) D) E) Ans: 3-Methyl-5-(1,4-dinitrobenzyl)-1-pentanal 3-Methyl-1-(2,5-dinitrophenyl)-5-pentanal 3-Methyl-5-(2,5-dinitrophenyl)pentanal 3-Methyl-5-(2,5-dinitrophenyl)pentanaldehyde 3-Methyl-5-(2,5-dinitrophenyl)pentaldehyde C Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 23. Which is the proper name for the structure shown? O Cl A) B) C) D) E) Ans: 3,5-Dimethyl-5-(4-chlorobenzyl)-1-pentanal 3-Methyl-5-(4-chlorophenyl)hexanol 3,5-Dimethyl-5-(4-chlorophenyl)-1-pentanaldehyde 3-Methyl-5-(4-chlorophenyl)-hexanaldehyde 3-Methyl-5-(4-chlorophenyl)hexanal E 174 Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 24. Which is the proper name for the structure shown below? Br O A) B) C) D) E) Ans: 7-Bromo-1,4-octynal 7-Bromo-1,4-octynone 2-Bromo-5,7-octynal 7-Bromo-7-methyl-1-heptyne-3-ketone 7-Bromo-1-octyn-4-one E Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 25. What is the correct structure for (R)-7-bromo-1-octyn-4-one? Br Br Br O O O II I III Br Br IV A) B) C) D) E) Ans: O V O I II III IV V A 175 Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 26. What is the correct structure for (S)-7-bromo-1-octyn-4-one? Br Br Br O O O II I III Br Br IV A) B) C) D) E) Ans: O V O I II III IV V C Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 27. Which is the IUPAC name for the structure shown below? Br A) B) C) D) E) Ans: H O (R)-5-Bromo-2-heptanal (S)-5-Bromo-2-heptanal (R)-5-Bromo-2-heptanone (S)-5-Bromo-2-heptanone (R)-3-Bromopentyl methyl ketone C 176 Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 28. Which is the IUPAC name for the structure shown below? H Br O A) B) C) D) E) Ans: (R)-5-Bromo-2-heptanal (S)-5-Bromo-2-heptanal (R)-5-Bromo-2-heptanone (S)-5-Bromo-2-heptanone (R)-3-Bromopentyl methyl ketone D Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 29. What is the correct structure for (R)-5-bromo-2-heptanone? Br H Br Br H H H O O II I III H Br H H Br O O V IV A) B) C) D) E) Ans: I II III IV V B 177 O Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 30. What is the correct structure for (S)-5-bromo-2-heptanone? Br H Br Br H H H O O II I III H Br H H Br O O V IV A) B) C) D) E) Ans: I II III IV V E Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 31. Which is the IUPAC name for the structure shown below? A) B) C) D) E) Ans: O 5-Cyclohexyl-2-hexanal 5-Cyclohexyl-2-hexanone 5-Cyclohexyl-5-methyl-2-pentanone 5-(1-Methylcyclohexyl)-2-pentanone 4-(1-Methylcyclohexyl)-2-butanone E 178 O Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 32. What is the correct structure for 4-(1-methylcyclohexyl)-2-butanone? I O II IV A) B) C) D) E) Ans: O O V III O III O O I II III IV V D Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 33. What is the correct structure for (S)-4-cyclohexyl-3-methyl-2-butanone? I O II IV A) B) C) D) E) Ans: O I II III IV V C 179 O V O Topic: Nomenclature Section: 16.2 Difficulty Level: Hard 34. What is the correct structure for (S)-4-cyclohexyl-3-methyl-2-butanone? I O II IV A) B) C) D) E) Ans: O III O V O I II III IV V E Topic: Physical Properties, Relationships, Stereochemistry Section: 16.3 Difficulty Level: Easy 35. Which of the compounds listed below would you expect to have the highest boiling point? (They all have approximately the same molecular weight.) A) Pentane B) 1-Butanol C) Butanal D) 1-Fluorobutane E) Diethylether Ans: B 180 O Topic: Reagents Section: 16.4 Difficulty Level: Easy 36. LiAlH4 (LAH) cannot be used to convert carboxylic acids to the corresponding aldehydes because: A) LAH is not sufficiently reactive. B) RCOOH is converted into RCOOLi. C) RCOOH is reduced to RCH2OH. D) RCOOH is reduced to RCH3. E) RCOOH is converted into R2C=O. Ans: C Topic: Reagents Section: 16.4 Difficulty Level: Easy 37. Identify the reagent(s) that would bring about the following reaction: CH3CH2CH2COCl CH3CH2CH2CHO A) H2/Ni B) Li/liq.NH3 C) LiAlH[OC(CH3)3]3, ether D) NaBH4, CH3OH E) LiAlH4, ether Ans: C 181 Topic: Reaction Products Section: 16.4 and previous chapters Difficulty Level: Medium 38. Select the structure of the major product in the following reaction. i) BH3 ? ii) H2O2,OH-, H2O A) B) C) D) E) Ans: Ethylbenzene 1-Phenylethanol Acetophenone 2-Phenylethanal Vinylbenzene D 182 Topic: Reaction Products Section: 16.4 and previous chapters Difficulty Level: Medium 39. Select the structure of the major product in the following reaction. i) BH3 ii) H2O2,OH-, H2O ? OH O OH II I III H O IV A) B) C) D) E) Ans: V I II III IV V D 183 Topic: Reaction Products Section: 16.4 Difficulty Level: Medium 40. What is the final product, Z, of the following synthesis? C H 1 . K M n O 4, O H 3 2 . H 3O heat X + O O C O A l ( t- B u ) 2 C O C H I A) B) C) D) E) Ans: -, S O C l2 3 II III I II III IV V C 184 Y 1 . L iA lH ( O - t- B u ) 3 e th e r, -7 8 oC 2 . H 2O O O O C H C O Li C O H IV V Z Topic: Synthesis Section: 16.4 Difficulty Level: Medium 41. Which of the following procedures would not yield 3-pentanone as a major product? C H 3C H 2M g B r A) H 3O + C H 3C H 2C N e th e r 1. O3 B) 2. Zn/H+ C) C H 3C H 2L i C H 3C H 2C N D) H 3O e th e r H CH3CH2MgBr ether C H 3C H 2C O 2H PCC H3O+ CH2Cl2 O E) + C H 3C H 2M g B r e th e r Ans: E 185 H 3O + Topic: Synthesis Section: 16.4 Difficulty Level: Medium 42. A good synthesis of H O w o u ld b e : H I H H 2O , H 2S O 4 H2O, H2SO4 H gSO I 4 HgSO4 H 1 . S ia 2B H II 2 . H 2O 2, N aO H H 1. DIBAL-H/-78oC CN 1. O II III 3 2. H2O 2. Zn, H O A c H IV III O H 1. K M nO 4, N aO H , heat 2 . H 3 O 1.+ O3 2. Zn/H+ OH IV A) B) C) D) E) Ans: 1. KMnO4, NaOH, heat 2. H3O+ I II III IV All of these are equally useful. B 186 Topic: Synthesis Section: 16.4 Difficulty Level: Medium 43. A good synthesis of H O w o u ld b e : H I H H 2O , H 2S O H g S HO 24O, H2SO4 I HgSO4 H 1 . S ia 2B H II 2 . H 2O 2, N aO H H III 1. DIBAL-H/-78oC COOCH3 1. O II IV 4 3 2. H2O 2. Zn, H O A c O H 1 . K MH n O 4 , N a O H , h e a t 2 . H 3O + III 1. O3 2. Zn/H+ OH IV A) B) C) D) E) Ans: 1. KMnO4, NaOH, heat 2. H3O+ I II III IV All of these are equally useful. B 187 Topic: Synthesis Section: 16.4 Difficulty Level: Medium 44. A good synthesis of H O w o u ld b e : H I H H 2O , H 2S O H2SO4 H g S HO 2O, 4 I HgSO4 H 1 . S ia 2B H II H 2 . H 2O 2, N aO H H 1. O II III IV 1. O3 3 2. Zn/H+ 2. Zn, H O A c O H 1. K M nO 4, N aO H , heat 2 . H 3O + COCl III A) B) C) D) E) Ans: 1. LiAl(OC(CH3)3)3H 2. H3O+ OH IV 4 1. KMnO4, NaOH, heat 2. H3O+ I II III IV All of these are equally useful. C 188 Topic: Synthesis Section: 16.4 Difficulty Level: Medium 45. A good synthesis of H O w o u ld b e : H I I H H 2O , H 2S O H gSO 4H2O, H2SO4 H 1 . S ia 2B H II 4 HgSO4 2 . H 2 O H2 , N a O H H 1. O III I I IV III 1. O3 3 2 . Z n , H O 2.A Zn/H c + O H 1. K M nO 4, N aO H , heat 2 . H 3O + PCC CH2Cl2 OH OH IV A) B) C) D) E) Ans: 1. KMnO4, NaOH, heat 2. H3O+ I II III IV All of these are equally useful. C 189 Topic: Synthesis Section: 16.4 Difficulty Level: Medium 46. A good synthesis of H O w o u ld b e : H I H H 2O , H 2S O H gSO I H 2.H2O2, NaOH 2 . H 2O 2, N aO H H III 1. DIBAL-H/-78oC CN 1. O II III 3 A) B) C) D) E) Ans: 2. H2O 2. Zn, H O A c O H 1 . COOCH K M n O 4 ,1.N DIBAL-H/-78 a O H , h e a t oC 3 2 . H 3O COCl IV 4 1. BH3 1 . S ia 2B H II IV 4 + 2. H2O 1. LiAl(OC(CH3)3)3H 2. H3O+ I II III IV All of these are equally useful. E 190 Topic: Synthesis Section: 16.4 Difficulty Level: Medium 47. Which synthesis or syntheses would yield propanal? PC C A) C H 3C H 2C H 2O H C H 2 C l2 O B) L iA lH [O C (C H 3 )3 ]3 C H 3C H 2C C l C) C H 3C CH e th e r, -7 8 o C 1 . S ia 2 B H 2 . H 2O 2, O H - D) All of these E) None of these Ans: D Topic: Reaction Products Section: 16.4 Difficulty Level: Hard 48. Select the structure of the major product in the following reaction. i) H2, Lindlar catalyst ii) O3 iii)Zn, CH3CO2H A) B) C) D) E) Ans: 4-Methylhexanal 4-Methyl-1-hexanol 3-Methylhexanal 4,10-Dimethyldodecane-6,7-dione 4,10-Dimethyldodecane-6,7-diol A 191 ? Topic: Reaction Products Section: 16.4 Difficulty Level: Hard 49. Select the structure of the major product in the following reaction. i) H2, P-2 ii) O3 iii)Zn, CH3CO2H A) B) C) D) E) Ans: ? 4-Methylhexanal 4-Methyl-1-hexanol 3-Methylhexanal 4,10-Dimethyldodecane-6,7-dione 4,10-Dimethyldodecane-6,7-diol A Topic: Reaction Products Section: 16.4 Difficulty Level: Hard 50. Select the structure of the major product in the following reaction. i) H2, Ni2B ii) O3 iii)Zn, CH3CO2H A) B) C) D) E) Ans: 4-Methylhexanal 4-Methyl-1-hexanol 3-Methylhexanal 4,10-Dimethyldodecane-6,7-dione 4,10-Dimethyldodecane-6,7-diol A 192 ? Topic: Reaction Products Section: 16.4 Difficulty Level: Hard 51. Select the structure of the major product in the following reaction. i) Li, NH3(l) ii) O3 iii)Zn, CH3CO2H A) B) C) D) E) Ans: 3-Methylhexanal 4-Methyl-1-hexanol 4-Methylhexanal 4,10-Dimethyldodecane-6,7-dione 4,10-Dimethyldodecane-6,7-diol C 193 ? Topic: Reaction Products Section: 16.4 Difficulty Level: Hard 52. Select the structure of the major product in the following reaction. i) H2, Lindlar catalyst ii) O3 iii)Zn, CH3CO2H O ? O OH H I H III II OH O OH O V IV A) B) C) D) E) Ans: I II III IV V A 194 Topic: Synthesis Section: 16.4 Difficulty Level: Hard 53. A good synthesis of H O w o u ld b e : H I H 2O , H 2S O H gSO 4 4 H 1 . S ia 2B H II 2 . H 2O 2, N aO H H 1. O III IV A) B) C) D) E) Ans: 3 2. Zn, H O A c O H 1. K M nO 4, N aO H , heat 2 . H 3O + I II III IV All of these are equally useful. B 195 Topic: Reaction Products Section: 16.5 and previous chapters Difficulty Level: Medium 54. Select the structure of the major product in the following reaction. H2SO4 ? HgSO4, H2O A) B) C) D) E) Ans: Ethylbenzene 1-Phenylethanol Acetophenone 2-Phenylethanal Vinylbenzene C Topic: Reaction Products Section: 16.5 and previous chapters Difficulty Level: Medium 55. Select the structure of the major product in the following reaction. H2SO4 HgSO4, H2O ? OH O II I III H O IV A) B) C) D) E) Ans: V I II III IV V C 196 Topic: Reaction Products Section: 16.5 Difficulty Level: Medium 56. Select the structure of the major product in the following reaction. i.) KMnO4, OH-, hot ? ii) H3O+ OH OH II I III OH O V IV A) B) C) D) E) Ans: I II III IV V E Topic: Reaction Products Section: 16.5 Difficulty Level: Medium 57. Select the structure of the major product in the following reaction. i.) KMnO4, OH-, hot + ii) H3O A) B) C) D) E) Ans: cyclopentanol 1-cyclopentylcyclopentane cyclopentanone cyclopentene 1-(1-hydroxycyclopentyl)-1-hydroxycyclopentane C 197 ? Topic: Synthesis Section: 16.5 Difficulty Level: Medium 58. Which of the reactions listed below would serve as a synthesis of acetophenone, O C 6H 5C C H ? 3 A) OH PCC CH2Cl2 B) C) C 6H 6 + C H 3C O C l C 6H 5C N + C H 3L i D) Answers A) and B) only E) Answers A), B), and C) Ans: E A lC l3 e th e r H 3O + Topic: Synthesis Section: 16.5 Difficulty Level: Medium 59. Which of the following would yield 3-pentanone as the major product? e th e r A) H 3O + C H 3C H 2C N + C H 3C H 2L i P ro d u ct ether B) H3O+ CN C) + MgBr PCC OH CH2Cl2 D) Two of these E) All of these Ans: E 198 Product Topic: Synthesis Section: 16.5 Difficulty Level: Medium 60. Which of the following is not a synthesis of benzophenone, O C 6H 5C C 6H ? 5 O A) C 6H B) C) 6 + C 6H 5C C l (C 6H 5)2C H O H (C 6H 5)2C H = C H D) A lC l3 H 2C rO 4 a c e to n e 1. O 3 2 2. Zn, H O A c PCC Ph2CHOH CH2Cl2 E) All of the above will give benzophenone. Ans: E Topic: Synthesis Section: 16.5 Difficulty Level: Hard 61. Which of the following is a synthesis of 3-heptanone? A) PCC 1 . C H 3C H 2M g B r C H 3C H 2C H 2C H 2C H 2O H C H 2C l2 2 . H 3O + + C H 3(C H 2)2C H 2L i B) H 3O C H 3C H 2C N e th e r P B r3 C H 3C H 2M g B r C) N aC N C H 3C H 2C H 2C H 2O H e th e r e th e r 1. O3 D) 2. Zn/H+ E) All of the above are syntheses of 3-heptanone. Ans: E 199 H 2C r2O a c e to n e H 3O + 4 Topic: Reaction Products Section: 16.5 Difficulty Level: Hard 62. What would be the product of the following reaction sequence? OH i) PCl3 ? ii) C6H6, AlCl3 O iii) Zn(Hg), HCl, heat O O OH OH I A) B) C) D) E) Ans: II I II III IV V E IV III V 200 Topic: Reaction Products Section: 16.5 Difficulty Level: Hard 63. What would be the product of the following reaction sequence? OH i) PCl5 ? ii) C6H6, AlCl3 O iii) Zn(Hg), HCl, heat O OH O OH II I IV A) B) C) D) E) Ans: III V I II III IV V E 201 Topic: Reaction Products Section: 16.5 Difficulty Level: Hard 64. What would be the product of the following reaction sequence? OH i) SOCl2 ? ii) C6H6, AlCl3 O iii) Zn(Hg), HCl, heat O OH O OH II I IV A) B) C) D) E) Ans: III V I II III IV V E 202 Topic: Reaction Products Section: 16.5 Difficulty Level: Hard 65. What would be the product of the following reaction sequence? OH O i) PCl3 ii) C6H6, AlCl3 iii) NaBH4, H2O ? O OH II I III OH OH A) B) C) D) E) Ans: I II III IV V D IV V 203 Topic: Reaction Products Section: 16.5 Difficulty Level: Hard 66. What would be the product of the following reaction sequence? OH O i) PCl3 ii) C6H6, AlCl3 iii) LiAlH4 iv) H2O ? O OH II I III OH OH IV A) B) C) D) E) Ans: V I II III IV V D 204 Topic: Reaction Products Section: 16.5 Difficulty Level: Hard 67. What would be the product of the following reaction sequence? OH O i) PCl3 ii) C6H6, AlCl3 iii) Zn(Hg), HCl, heat ? O OH II I III OH OH IV A) B) C) D) E) Ans: V I II III IV V A 205 Topic: Reaction Products Section: 16.5 Difficulty Level: Hard 68. The product, E, of the following reaction sequence, P C l5 C 6H 6 C H 3C H 2C O O H C D A lC l3 O C H 2C H 2C H A) B) C) D) E) Ans: I I II III IV V C 3 N aB H C H C H 2C H 3 II III 206 E C H 3O H O H C O C H 2C H 4 would be: O 3 C C H 2C H IV 3 C H (C H 3)2 V Topic: Reaction Products Section: 16.5 Difficulty Level: Hard 69. The product, D, of the following sequence of reactions O S O C l2 C H 3C H 2C O H A to lu e n e A lC l3 Z n (H g ) B H C l + C D (d is c a rd ) would be: O C H C H 2C H 2C H 3 3 C H 3C H 2C C H I C H A) B) C) D) E) Ans: I II III IV V A O C H 2 II 3 C H 2C H 2C H 2C l III C H IV C H C H C H 3 V 207 C H 2C H 2C C l 3 3 3 Topic: Reaction Products Section: 16.5 Difficulty Level: Hard 70. The product, E, of the following reaction sequence, OH C6H6 PCl5 C LAH D AlCl3 E O would be: O C H 2C H 2C H A) B) C) D) E) Ans: O H C O C H 2C H 3 I C H C H 2C H 3 II I II III IV V C III O 3 C C H 2C H C H (C H 3)2 3 IV V Topic: Reaction Products Section: 16.5 Difficulty Level: Hard 71. What is the final product of this synthetic sequence? B enzene A) B r2 M g F e C l3 e th e r O C 6H 5C C 6H B) C) D) 1 . C 6H 5C H O 2. H 3O 5 p-BrC6H4CH2C6H5 C6H5CH2COOH O C 6H 5C H 2C C 6H 5 E) C6H5CH2C6H5 Ans: A 208 + H 2C r2O a c e to n e 4 ? Topic: Reagents Section: 16.6 Difficulty Level: Easy 72. Which of these will not catalyze the reaction of a weak nucleophile with the carbonyl group of an aldehyde or ketone? A) IB) H3O+ C) AlCl3 D) BF3 E) ZnCl2 Ans: A Topic: Carbonyl Reactivity Section: 16.6 Difficulty Level: Medium 73. What, in general, is the order of decreasing reactivity of these carbonyl compounds towards nucleophilic reagents? H O C H 3C C H I A) B) C) D) E) Ans: 3 C H 3C H O O II I > III > IV > II > V IV > II > I > III > V V > III > I > II > IV I > IV > II > III > V III > V > IV > II > I B (C H 3)3C C C H III 209 3 O HC O IV (C H 3)3C C C (C H 3)3 V Topic: Carbonyl Reactivity Section: 16.6 Difficulty Level: Medium 74. What, in general, is the order of increasing reactivity of these carbonyl compounds towards nucleophilic reagents? H O C H 3C C H I A) B) C) D) E) Ans: C H 3C 3 H O O (C H 3)3C C C H II I < III < V < II < IV IV < II < I < III < V V< III < I < II < IV II< I < V < III < IV III < V < IV < II < I C 3 O HC III (C H 3)3C C C (C H 3)3 O IV V Topic: Reaction Products Section: 16.5 and 16.6 Difficulty Level: Medium 75. The product, K, of the following sequence of reactions C H B enzene 3 C H 3C H C O C l I A lC l3 O H C H 3C H 2M g B r e th e r H 3O J + K would be: O H H O O O A) B) C) D) E) Ans: I I II III IV V B II III 210 IV V Topic: Reaction Products Section: 16.5 and 16.6 Difficulty Level: Medium 76. The product, K, of the following sequence of reactions would be: MgBr AlCl3 I Cl J H3O+ K heat ether (-H2O) O O HO I III II OH V IV A) B) C) D) E) Ans: I II III IV V D 211 Topic: Reaction Products Section: 16.7 Difficulty Level: Easy 77. Dissolving benzaldehyde in methyl alcohol establishes an equilibrium with what compound? O H A) B) C 6H 5C H O C H O C 6H 5C O C H C) D) E) Ans: 3 3 C6H5C(OCH3)3 Answers A) and B) Answers B) and C) A Topic: New Functional Groups Section: 16.7 Difficulty Level: Easy 78. Which of the following compounds is an acetal? O O OCH3 A) B) C) D) E) Ans: O O I I II III IV None of these C O OH II O III 212 O O IV Topic: New Functional Groups Section: 16.7 Difficulty Level: Easy 79. Which is the general formula for a thioacetal? H A) B) R C S R C H SR ' C) O H RC HSR' D) SH R C H SR ' E) SR ' R CHO R ' Ans: D SR' Topic: New Functional Groups Section: 16.7 Difficulty Level: Easy 80. Which compound is an acetal? O I A) B) C) D) E) Ans: OH O II OCH3 O O OH O III I II III IV All of the above B 213 IV Topic: New Functional Groups Section: 16.7 Difficulty Level: Easy 81. Which compound is a hemiacetal? O OH II I A) B) C) D) E) Ans: O OCH3 O O OH O III IV I II III IV All of the above A Topic: Synthesis Section: 16.7 Difficulty Level: Easy 82. Which of the following reactions would yield benzaldehyde? O H A) C 6H 5C H 2C l H 2O heat B) H 3O + C 6H 5C H (O C H 3)2 C) 1 . L iA lH 4 , e th e r C 6H 5C O O H 2 . H 2O D) Answers A) and B) E) Answers A), B), and C) Ans: B 214 Topic: Reagents Section: 16.7 Difficulty Level: Easy 83. Acetals are unstable in the presence of an aqueous solution of which of these? A) HCl B) NaOH C) KHCO3 D) Na2CO3 E) NaCl Ans: A Topic: Reaction Products Section: 16.7 Difficulty Level: Medium 84. What new compound will eventually be formed when HCl is added to a solution of pentanal in methanol? O A) O O B) C) D) Cl OH O O E) Ans: A OH Cl O 215 Topic: Reaction Products Section: 16.7 Difficulty Level: Medium 85. What new compound will be formed when gaseous HCl is added to a solution of propanal in methanol? O A) C H 3C H 2C O C H O B) 3 C H 3C H 2C O H C) D) CH3CH2CH(OCH3)2 C H 3C H 2C H O C H 3 O H E) None of the above Ans: C Topic: Reaction Products Section: 16.7 Difficulty Level: Medium 86. What is the major product of the following reaction sequence? OH, HCl OCH3 i) HO ? O ii) LAH, Et2O O iii) H2O, H3O O OH HO + OH O HO I III OH OH O O A) B) C) D) E) Ans: I II III IV V E O II IV V 216 Topic: Synthesis Section: 16.7 Difficulty Level: Medium 87. Which sequence of reactions would be utilized to convert O A) B) C) D) E) Ans: C O 2C H 3 in to O C H 3 C C H 3 ? O H 2CH3MgBr, then NH4+ HOCH2CH2OH, H3O+; LiAlH4, ether; 2CH3MgBr, then NH4+ HOCH2CH2OH, H3O+; 2CH3MgBr, then NH4+ HOCH2CH2OH, H3O+; H2, Pt; CH3OH, NH4+ None of the above C Topic: Reagents Section: 16.7 Difficulty Level: Medium 88. Which reagent(s) could be used to carry out the following transformation? O ? A) B) C) D) E) Ans: Zn(Hg), HCl, reflux LiAlH4, ether HSCH2CH2SH, BF3; then Raney Ni (H2) All of the above Two of the above E 217 Topic: Carbonyl Reactivity Section: 16.7 Difficulty Level: Medium 89. Which of these gem-diols is expected to be the most stable? O H A) C F 3C C F B) C) 3 O H CH3CH(OH)2 O H C H 3C C H 3 O H D) C6H5CH(OH)2 E) ClCH2CH(OH)2 Ans: A Topic: Carbonyl Reactivity Section: 16.7 Difficulty Level: Medium 90. Which of these gem-diols is expected to be the least stable? O H A) C F 3C C F B) C) 3 O H CH3CH(OH)2 O H C H 3C C H 3 O H D) C6H5CH(OH)2 E) ClCH2CH(OH)2 Ans: C 218 Topic: Reaction Products Section: 16.7 Difficulty Level: Hard 91. What new compound will eventually be formed when HCl is added to a solution of pentanal in methanol? A) 1-Chloro-1-methoxypentane B) 1,1-Dimethoxypentane C) 1,1-Dihydroxypentane D) 1,1-Dichloropentane E) 1-Chloro-2-methoxypentane Ans: B Topic: Reagents Section: 16.7 Difficulty Level: Medium 92. The following reduction can be carried out with which reagent(s)? ? A) B) C) D) E) Ans: O Zn(Hg), HCl i) HSCH2CH2SH, BF3 ; ii)Raney Ni (H2) NaBH4, CH3OH A&B A&C D 219 Topic: Synthesis Section: 16.4 and 16.7 Difficulty Level: Medium O 93. Which of the following procedures would not yield ( C H 3 ) 2 C H C H as a product? PC C I O H C H 2 C l2 S O C l2 II C O 2H A) B) C) D) E) Ans: Zn 3 H O A c K M nO IV V e th e r, -7 8 oC O III L i A l H ( O - t- B u ) 3 O H O 4 H 3O + N aO H H 3O + O I II III IV V D 220 Topic: Reaction Products Section: 16.5 and 16.7 Difficulty Level: Medium 94. The product, E, of the following sequence of reactions OH SH PCl5 Raney Ni HS D B A H2 BF3 O + C (discard) would be: O OH III II I O Cl V IV A) B) C) D) E) Ans: I II III IV V C 221 E Topic: Reaction Products Section: 16.5 and 16.7 Difficulty Level: Medium 95. The product, E, of the following sequence of reactions OH SH PCl5 Raney Ni HS D B A H2 BF3 O + C (discard) would be: O III II I O Cl V IV A) B) C) D) E) Ans: I II III IV V C 222 E Topic: Reaction Products Section: 16.5 and 16.7 Difficulty Level: Hard 96. What would be the product of the following reaction sequence? OH i) SOCl2 ? ii) C6H6, AlCl3 O iii) HSCH2CH2SH, BF3 iv) Raney Ni (H2) O O OH OH II I IV A) B) C) D) E) Ans: III V I II III IV V E 223 Topic: Reaction Products Section: 16.5 and 16.7 Difficulty Level: Hard 97. What would be the product of the following reaction sequence? OH O i) PCl3 ii) C6H6, AlCl3 iii) HSCH2CH2SH, BF3 iv) Raney Ni (H2) O ? OH II I III OH IV A) B) C) D) E) Ans: V I II III IV V B Topic: Reagents Section: 16.8 Difficulty Level: Medium 98. Which reagent will not differentiate between 3-butenal and 2-butanone? A) Br2/CCl4 B) Ag2O,OHC) H2NNHC6H5 D) KMnO4,OHE) None of these Ans: C 224 Topic: Reagents Section: 16.8 Difficulty Level: Medium 99. H H The compound C 6 H 5 C N N C C 6 H benzaldehyde with which compound? A) Ammonia B) Hydrazine C) Nitrogen D) Phenylhydrazine E) Hydroxylamine Ans: B 5 is produced by the reaction of an excess of Topic: Physical Properties, Relationships, Stereochemistry Section: 16.8 Difficulty Level: Medium 100. Stereoisomers can exist in the case of which of the following? A) The hydrazone of butanone B) The oxime of acetone C) The phenylhydrazone of cyclohexanone D) The cyclic acetal formed from propanal and ethane-1,2-diol E) The imine of cyclopentanone Ans: A Topic: Physical Properties, Relationships, Stereochemistry Section: 16.8 Difficulty Level: Medium 101. Stereoisomers can exist in the case of which of the following? A) The hydrazone of benzophenone B) The oxime of 2-methylcyclopentanone C) The phenylhydrazone of 4-methylcyclohexanone D) The imine of cyclopentanone E) Two of the above Ans: B 225 Topic: Reactions of Aldehydes and Ketones Section: 16.8 Difficulty Level: Medium 102. Which of the following is formed when 3-methylcyclopentanone reacts with hydroxylamine? N-NH-C6H5 N-NH2 I N-OH II III NO2 O N A) B) C) D) E) Ans: I II III IV V C N H NH2 N N H IV V 226 NO2 Topic: Reactions of Aldehydes and Ketones Section: 16.8 Difficulty Level: Medium 103. Which of the following is formed when 4-methylpentanal reacts with phenylhydrazine? N-C6H5 N-NH-C6H5 I N-NH2 II III O N IV A) B) C) D) E) Ans: N H N=N-C6H5 NH2 V I II III IV V A 227 Topic: Reactions of Aldehydes and Ketones Section: 16.8 Difficulty Level: Medium 104. Which of the following is formed when 2,2,3-trimethylcyclohexanone reacts with hydroxylamine? N-NH-C6H5 N-NH2 I N-OH III II NO2 O N A) B) C) D) E) Ans: I II III IV V C N H NH2 N N H IV V 228 NO2 Topic: Reactions of Aldehydes and Ketones Section: 16.8 Difficulty Level: Medium 105. Which of the following is formed when 2,2,3-trimethylcyclohexanone reacts with hydrazine? N-NH-C6H5 N-NH2 I N-OH III II NO2 O N A) B) C) D) E) Ans: I II III IV V B N H NH2 N N H IV V 229 NO2 Topic: Reaction Products Section: 16.9 Difficulty Level: Medium 106. The product, C, of the following reaction sequence, O C H 3C C H + 3 C H A) C H B) C) C N H C N C 4H 7N O 3 C CO O H 2 CH3CH2COOCH3 C H 3C H C H 3 C N D) CH3CH=CHCOOH E) None of these Ans: A 230 H 2O H 2S O heat C 4 would be: Topic: Reaction Products Section: 16.9 Difficulty Level: Medium 107. The product, D, of the following reaction sequence, O - CN HCN HCl C4H7NO H2 O heat C H A) C H 3 C CO O H 2 B) C) CH3CH2COOCH3 D) E) CH3CH=CHCOOH C H 3C H C H 3 C N HO COOH Ans: E 231 D would be: Topic: Reaction Products Section: 16.9 Difficulty Level: Medium 108. What is the major product of the following reaction sequence? HCN H3O+ LiAlH4 ? O OH OH CN NH2 CN OH III II I OH COOH V A) B) C) D) E) Ans: I II III IV V C 232 IV Topic: Reaction Products Section: 16.9 Difficulty Level: Medium 109. What is the major product of the following reaction sequence? HCN HCl O H2O heat OH OH OH CN NH2 CN OH III II I OH COOH V A) B) C) D) E) Ans: I II III IV V E 233 IV Topic: Reaction Products Section: 16.9 Difficulty Level: Medium 110. What is the major product of the following reaction sequence? O H C N H 2S O 4 H 2O heat C N N O S O 3H C N C O H H O S O 3H C N H O A) B) C) D) E) Ans: I I II III IV V B II III 234 IV V 2 Topic: Physical Properties, Relationships, Stereochemistry Section: 16.9 Difficulty Level: Medium 111. In which of the following reactions is the final product expected to be formed as a racemic mixture? H A) C 6H 5M g B r + C 6H 5C O O B) H CN + C H 3C C H C) 3 O H + HCN H D) C H 3C + O O E) x s C H 3O H C H 3C H C H 2C O C 2H C H 5 + H Cl + (i-B u )2 A lH 3 Ans: C 235 Topic: Reaction Products Section: 16.9 Difficulty Level: Hard 112. What is the major product of the following reaction sequence? H2SO4 HCN LiAlH4 O H3O+ ? H2 O heat OH OH CN NH2 CN OH III II I OH COOH V A) B) C) D) E) Ans: I II III IV V D 236 IV Topic: Reaction Products Section: 16.9 Difficulty Level: Hard 113. What is the major product of the following reaction sequence? HCN LiAlH4 HCl H3O+ ? O H2O heat OH OH OH CN NH2 CN OH III II I OH COOH V A) B) C) D) E) Ans: I II III IV V D 237 IV Topic: Reaction Products Section: 16.10 Difficulty Level: Medium 114. The product, H, of the following reaction sequence, C 6H 5C H 2B r + would be: A) (C 6H 5)3P C H 3 C 6H 5C H 2C C 6H 5 O H O B) C) F C 6H 5C H 2C C 6H 5 C 6H 5C H C H C C 6H 5 O D) E) C6H5CH2CH=CHC6H5 C 6H 5C H C CH C 6H 3 5 Ans: E 238 C 6H 5L i e th e r O G C 6H 5C C H 3 H Topic: Reaction Products Section: 16.10 Difficulty Level: Medium 115. What would be the final product? (C 6H 5)3P C H 3I A) C 6H 5C C H C 6H 5C C H 2 C H3 C 6H 5 C 6H 5C C H CH 3 3 C6H5CH=CHCH3 O H C 6H 5C C H E) C 6H 5L i e th e r B) C) D) O CH C 6H 5C H 3 3 C C 6H CH 5 3 Ans: A 239 3 ? Topic: Reaction Products Section: 16.10 Difficulty Level: Medium 116. What would be the final product? O CH3I A) C 6H 5C C H C 6H 5C C H CH 3 3 C6H5CH=CHCH3 O H C 6H 5C C H E) 2 C H3 C 6H 5 B) C) D) NaH P(OEt)3 + CH C 6H 5C H 3 3 C C 6H CH 5 3 Ans: A 240 ? Topic: Reaction Products Section: 16.10 Difficulty Level: Medium 117. What is the reactant W in the synthesis given below? O Ph3P + A) B) C) D) E) Ans: W C6H5Li Wittig reagent Cyclopentanone Cyclopentene Cyclopentanol Bromocyclopentane Triphenylphosphine oxide D 241 Topic: Synthesis Section: 16.10 Difficulty Level: Medium 118. Which reaction sequence would be used to prepare ? I O II III IV A) B) C) D) E) Ans: 1 . e th e r + O H M gB r + (C 6H 5)3P + 2. H 3O 2 C H 3M gB r H N i 1 . e th e r 2 . H 3O 2 H + C 6H 5L i 2 N i c y c lo p e n ta n o n e C l H 2 N i O C H 3M gB r H 3O + e th e r I II III IV All of the above would yield the product. C 242 Topic: Synthesis Section: 16.10 Difficulty Level: Medium 119. Which Wittig reagent would be used to synthesize ? C H = P (C 6H 5)3 C H 3C H = P (C 6H 5)3 A) B) C) D) E) Ans: P (C 6H 5)3 I II I II III IV Either I or II could be used. E C H 3C H 2C H = P (C 6H 5)3 III IV Topic: Reaction Products Section: 16.10 Difficulty Level: Hard 120. The product, H, of the following reaction sequence, O Br would be: A) C H 3 C 6H 5C H 2C C 6H 5 O H O B) C) F P(OEt)3 + C 6H 5C H 2C C 6H 5 C 6H 5C H C H C C 6H 5 O D) E) C6H5CH2CH=CHC6H5 C 6H 5C H C CH C 6H 3 5 Ans: E 243 NaH G H Topic: Reaction Products Section: 16.12 Difficulty Level: Medium 121. Predict the major organic product of the following reaction: A g (N H 3)2+ H O O A) B) C) D) E) Ans: I II III IV V B O O O H O 2C O H 3C I ? H 2O II H H 3C H 3C III H O H O O O IV V Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 122. A compound with formula C5H10O gives two signals only, both singlets, in the 1H NMR spectrum. Which of these structures is a possible one for this compound? O A) B) C H 3C H 2C C H 2C H O C) (C H 3)2C H C C H H (C H 3)3C C D) 3 O H C H 3C H 2C H C C H 3 O 3 H E) (C H 3)2C H C H 2C O Ans: C 244 Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 123. A compound with formula C5H10O gives two signals only, one a triplet and the other a quartet, in the 1H NMR spectrum. Which of these structures is a possible one for this compound? O A) B) C H 3C H 2C C H 2C H O C) (C H 3)2C H C C H H (C H 3)3C C D) 3 O H C H 3C H 2C H C C H 3 O 3 H E) (C H 3)2C H C H 2C O Ans: A Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 124. The 1H NMR spectrum of a compound with formula C7H14O gives three signals. Which of these structures is a possible one for this compound? A) 2-Heptanone B) 3-Heptanone C) 2,4-Dimethyl-3-pentanone D) 2,2-Dimethyl-3-pentanone E) Two of the above Ans: D 245 Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 125. The 1H NMR spectrum of a compound with formula C7H14O gives two signals. Which of these structures is a possible one for this compound? A) 2-Heptanone B) 3-Heptanone C) 2,4-Dimethyl-3-pentanone D) 2,2-Dimethyl-3-pentanone E) Two of the above Ans: C Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 126. The 13C NMR spectrum of a compound with formula C7H14O gives three signals. Which of these structures is a possible one for this compound? A) 2-Heptanone B) 3-Heptanone C) 2,2-Dimethyl-3-pentanone D) 2,4-Dimethyl-3-pentanone E) Two of the above Ans: D Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 127. The 13C NMR spectrum of a compound with formula C7H14O gives five signals. Which of these structures is a possible one for this compound? A) 2-Heptanone B) 3-Heptanone C) 2,2-Dimethyl-3-pentanone D) 2,4-Dimethyl-3-pentanone E) Two of the above Ans: C 246 Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 128. The 1H NMR spectrum of a compound with formula C7H14O gives a doublet at 9.2 ppm. Which of these structures is a possible one for this compound? A) 2-Methyl-3-hexanone B) 2-Methylhexanal C) 2,2 -Dimethylpentanal D) 2,2-Dimethyl-3-pentanone E) Two of the above Ans: B 247 SHORT ANSWER QUESTIONS Topic: Synthetic Strategy Section: 16.4 Difficulty Level: Medium 129. Suggest a synthetic strategy for the synthesis of 4-methylpentanal from 3-methyl-1bromobutane. Ans: i. DIBAL-H O NaCN CN Br ii. H2O Topic: Reaction Sequence Section: 16.4 Difficulty Level: Hard 130. Complete the following reaction sequence, giving structural details of all significant intermediates X, Y, and final product Z. 1 . L iA lH ( O - t- B u ) 3 1 . K M n O 4, O H , h eat S O C l2 e th e r, -7 8 oC C H 3 X Y 2 . H 2O 2 . H 3O + Ans: COOH O X C O A l ( t- B u ) 2 I COCl O YC O C H O 3 II Z C H III 248 O CHO O C O Li IV C O H V Z Topic: Synthetic Strategy Section: 16.5 Difficulty Level: Medium 131. Suggest a synthetic strategy for the synthesis of 3-heptanone from 1-bromobutane. i. C2H5Li, Et2O Ans: NaCN CN Br ii. H3O+ O Topic: Synthetic Strategy Section: 16.5 Difficulty Level: Hard 132. Suggest a synthetic strategy for the synthesis of 4-methylpentanal from 3-methyl-1bromobutane. HBr i. DIBAL-H NaCN CN Br ii. H2O ROOR Ans: Topic: Synthetic Strategy Section: 16.5 Difficulty Level: Hard 133. Suggest a synthetic strategy for the synthesis of 6-methyl-3-heptanol from 4methylpentanenitrile, (CH3)2CHCH2CH2CN. Ans: i. DIBAL-H CN ii. H2O OH iii. C2H5MgBr, Et2O iv. H3O+ OR CN i. C2H5MgBr, Et2O ii. H3O+ OH iii. NaBH4, H2O 249 O Topic: Synthetic Strategy Section: 16.5 Difficulty Level: Hard 134. Suggest a synthetic strategy for the synthesis of 3-heptanone from 1-butene. Ans: HBr i. C2H5Li, Et2O NaCN CN ii. H O+ Br 3 ROOR O Topic: Reaction Sequence Section: 16.5 Difficulty Level: Hard 135. Complete the following reaction sequence, giving structural details of all significant intermediates. i. Br2, h ii. Mg, CH3CH2CN iii. H3O+ iv. NaBH4 ? Ans: O Br2, h Br i. Mg, CH CH CN 3 2 ii. H3O+ 250 NaBH4 HO Topic: Reaction Sequence Section: 16.5 Difficulty Level: Hard 136. Complete the following reaction sequence, giving structural details of all significant intermediates. i. O3 i. EtMgBr ? + ii.Zn, CH3CO2H ii. H3O , heat O Ans: O i. EtMgBr ii. H3O+, heat i. O3 ii.Zn, CH3CO2H HO O O Topic: Reaction Sequence Section: 16.5 Difficulty Level: Hard 137. Complete the following reaction sequence, giving structural details of all significant intermediates and the final product. B r2 M g 1 . C 6H 5C H O H 2C r2O 4 B enzene ? F e C l3 e th e r a c e to n e 2. H 3O + O OH Ans: Br MgBr Topic: Relative Reactivity Section: 16.6 Difficulty Level: Medium 138. Aldehydes are more reactive than ketones towards nucleophilic substitution because of both steric and electronic factors. Briefly explain. a. Steric reasons: ______________. b. Electronic reasons: __________. Ans: a. aldehydes have the small hydrogen substituent on one side, so less steric crowding than ketones b. aldehydes have only one electron-releasing group to partly neutralize/stabilize the partial positive charge at the carbonyl carbon while ketones have two 251 Topic: Hemiacetals Section: 16.7 Difficulty Level: Easy 139. A compound with an OH and OR group attached to the same carbon is known as a(n) _____________. Ans: hemiacetal Topic: Hydrates Section: 16.7 Difficulty Level: Easy 140. A compound with two OH groups attached to the same carbon is known as a(n) _________. Ans: hydrate or gem-diol Topic: Acetals Section: 16.7 Difficulty Level: Easy 141. A compound with two OR groups attached to the same carbon is known as a(n) _________. Ans: acetal Topic: Reaction Sequence Section: 16.7 Difficulty Level: Medium 142. Complete the following reaction sequence, giving structural details of all significant intermediates and the final product. O H H+ OH Ans: O OH H H+ O OH 252 Topic: Reaction Sequence Section: 16.7 Difficulty Level: Hard 143. In the total synthesis of the Cecropia juvenile hormone, the following sequence of reactions were used. Draw the intermediate and final product formed. HO / H+ H 1. CH3Li O ? 2. H+/H2O O Ans: HO O O H / H+ H O 1. CH3Li 2. H+/H2O O O HO H HO CH3 Topic: Reaction Sequence Section: 16.7 Difficulty Level: Hard 144. Complete the following reaction sequence, giving structural details of all significant intermediates. O H 1. OsO4 2. NaHSO3 ? + H Ans: O OH H 1. OsO4 2. NaHSO3 OH H+ O O 253 Topic: Reaction Sequence Section: 16.7 Difficulty Level: Hard 145. Complete the following reaction sequence, giving structural details of all significant intermediates and the final product. O KMnO4, OH-, heat H+ + HO H+ H ? H2 O O Ans: O + O H+ HO KMnO4, OH-, heat H O O O H O O H O O O + H2O HO OH Topic: Functional Group Tests Section: 16.8 Difficulty Level: Easy 146. 2,4-DNP is a reagent frequently used for functional group tests; it detects the presence of _____________. Ans: aldehydes and ketones Topic: Imines Section: 16.8 Difficulty Level: Easy 147. A compound containing a C=N double bond is known as a(n) __________. Ans: imine Topic: Functional Group Tests Section: 16.8 Difficulty Level: Easy 148. Oximes are formed when aldehydes and ketones react with _______________. Ans: hydroxylamine, NH2OH 254 Topic: Cyanohydrins Section: 16.9 Difficulty Level: Easy 149. A compound with an OH and CN group attached to the same carbon is known as a(n) _____________. Ans: cyanohydrin Topic: Wittig Reaction Section: 16.10 Difficulty Level: Easy 150. The reaction between a phosphorus ylide and an aldehyde or ketone is called the ___________ reaction. Ans: Wittig Topic: Wittig Reaction Section: 16.10 Difficulty Level: Easy 151. The driving force for the Wittig reaction is the formation of the very strong _______________ bond in _______________. Ans: P-O bond; triphenylphosphine oxide Topic: General Section: 16.10 Difficulty Level: Hard 152. The conversion of a trans epoxide to a cis alkene using triphenylphosphine is an example of a ______________reaction. Ans: stereospecific Topic: General Section: 16.10 Difficulty Level: Hard 153. The conversion of a cis epoxide to a trans alkene using triphenylphosphine is an example of a ______________reaction. Ans: stereospecific 255 Topic: Synthetic Strategy Section: 16.10 Difficulty Level: Hard 154. Cis-stilbene (cis-1,2-diphenylethene) can be prepared in high yield from its trans diastereomer. Propose a reasonable synthesis. Ph H H H H Ph Ph Ph multiple steps cis-stilbene trans-stilbene Ans: Ph H m-CPBA H Ph O Ph H H Ph 256 O PPh3 H H Ph3P Ph H Ph Ph H Ph Topic: Mechanisms Section: 16.10 Difficulty Level: Hard 155. Draw a complete mechanism, using arrow convention to indicate electron movement, for the following transformation: O H3C H H + PPh3 + CH3 H H H3C Ph3P O CH3 Ans: O H3C H O H3C H + H O PPh3 H H PPh3 H3C CH3 H O PPh3 H PPh3 rotation 180o as shown CH3 H H3C H 257 CH3 H + H3C H3C CH3 Ph3P O Topic: Mechanisms Section: 16.10 Difficulty Level: Hard 156. Draw a complete mechanism, using arrow convention to indicate electron movement, for the following transformation: O H H3C H + PPh3 + CH3 H3C H H Ph3P O CH3 Ans: O H H3C O H3C H + H O PPh3 CH3 H PPh3 H H3C CH3 O PPh3 H3C PPh3 rotation 180o as shown CH3 CH3 H Ph3P CH3 H Topic: Functional Group Tests Section: 16.12 Difficulty Level: Easy 157. The Tollens test, used in conjunction with 2,4-DNP, can distinguish between ______________ and _______________. Ans: aldehydes and ketones Topic: Functional Group Tests Section: 16.12 Difficulty Level: Easy 158. What reagent would help you distinguish between acetophenone and 2methylbenzaldehyde? Ans: Tollen’s Reagent 258 CH3 H + H H O Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 159. Explain clearly how you might use 1H NMR to distinguish between 2-phenylacetaldehyde and acetophenone. Ans: A quick inspection of 1H NMR of the two substances would allow easy identification and distinction between them: the expected 1H NMR spectra of the two substances are described below. 2-Phenylacetaldehyde Acetophenone C6H5CH2CHO and C6H5COCH3 3 signals 2 signals approximate ppm approximate ppm doublet (-CH2-) 2.5 singlet (-CH3) 2.0 multiplet (C6H5) 7 multiplet (C6H5) 7.2 triplet(-CHO) 9 Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 160. Propose a structure that fits the following spectroscopic data: C5H10O IR: 1720 cm−1 1 H NMR: 1.9 (triplet, 3H), 1.7 (sextet, 2H), 2.1 (singlet, 3H), 2.4 (triplet, 2H) O CH3CH2CH2CCH3 Ans: 259 Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 161. Propose a structure that fits the following spectroscopic data: C5H10O IR: 1720 cm−1 1 H NMR: 1.1 (triplet, 3H), 2.4 (quartet, 2H) Ans: O Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 162. Propose a structure that fits the following spectroscopic data: C9H10O IR: 1680 cm−1 1 H NMR: 1.25 (triplet, 3H), 3.0 (quartet, 2H), 7-8 (complex multiplet, 5H) O Ans: 260 Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 163. Propose a structure that fits the following spectroscopic data: C7H6O IR: 1703 cm−1 1 H NMR: 7-8 (complex multiplet, 5H), 10.0 (singlet, 1H) O H Ans: Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 164. Propose a structure that fits the following spectroscopic data: C3H6O IR: 1730 cm−1 1 H NMR: 1.1 (triplet, 3H), 2.5 (doublet of quartets, 2H), 9.8 (doublet, 1H) H Ans: O 261 Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 165. Propose a structure that fits the following spectroscopic data: C5H10O IR: 1716 cm−1 Broadband decoupled 13C NMR: 7.93, 35.50, 212.07 DEPT Experiments show: signal at 7.93 as CH3 and signal at 35.50 as CH2 Ans: O Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 166. Propose a structure that fits the following spectroscopic data: C5H10O IR: 1717 cm−1 Broadband decoupled 13C NMR: 13.70, 17.41, 29.78, 45.71, 208.93 DEPT Experiments show: signals at 13.70, 29.78 as CH3 and signals at 17.41, 45.71 as CH2 O CH3CH2CH2CCH3 Ans: 262 Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 167. Propose a structure that fits the following spectroscopic data: C4H8O IR: 1728 cm−1 Broadband decoupled 13C NMR: 13.71, 15.69, 45.82, 202.80 DEPT Experiments show: signal at 13.71 as CH3 and signals at 15.69, 45.82 as CH2 O Ans: H Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 168. Propose a structure that fits the following spectroscopic data: C6H12O IR: 1708 cm−1 Broadband decoupled 13C NMR: 24.61, 26.42, 44.31, 213.81 DEPT Experiments show: signals at 24.61, 26.42 as CH3 Ans: O 263 Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 169. Propose a structure that fits the following spectroscopic data: C4H8O IR: 1737 cm−1 Broadband decoupled 13C NMR: 15.48, 41.07, 204.86 DEPT Experiments show: signal at 41.07 as CH and signal at 15.48 as CH3 H Ans: O Topic: Spectroscopy Section: 16.13 Difficulty Level: Medium 170. Propose a structure that fits the following spectroscopic data: C5H10O IR: 1728 cm−1 Broadband decoupled 13C NMR: 22.59, 23.57, 52.66, 202.71 DEPT Experiments show: signal at 23.57 as CH, signal at 22.59 as CH3, and signal at 52.66 as CH2. O Ans: H 264 Topic: Spectroscopy Section: 16.13 Difficulty Level: Hard 171. Acetaldehyde is reacted with excess methanol in acid. The product was isolated and gave the following 1H NMR spectroscopic data: 1.3 (doublet, 3H) 3.4 (singlet, 6H) 4.6 (quartet, 1H) Propose a structure consistent with this information. Ans: O O 265