Testbank 4 Nomenklatur konform+ svar PDF

Preview

Summary

testbank for quizzes. it is very helpful hope this helps you....

Description

Chapter 4

Chapter 4

4. A correct IUPAC name for the following compound is:

MULTIPLE CHOICE QUESTIONS Part 4 – Nomenklatur -konformation (Answers on pages 21-22) Uppgifter markerade * är överkurs Topic: Nomenclature 1.

A) B) C) D) E)

The IUPAC name for 6-Ethyl-3,4-dimethylheptane 2-Ethyl-4,5-dimethylheptane 3,4,6-Trimethyloctane 3,5,6-Trimethyloctane 2-(1-Methylpropyl)-4-methylhexane

is:

An IUPAC name for is: 5-Methyl-4-(1-methylpropyl)hexane 2-Methyl-3-(1-methylpropyl)hexane 2-Methyl-3-(2-methylpropyl)hexane 3-Methyl-4-(1-methylethyl)heptane 5-Methyl-4-(1-methylethyl)heptane

5. A) B) C) D) E)

Which of the following pairs of compounds represent pairs of constitutional isomers? 2-Methylbutane and pentane 2-Chlorohexane and 3-chlorohexane sec-Butyl bromide and tert-butyl bromide Propyl chloride and isopropyl chloride All of the above

6. Which of the following is bicyclo[3.2.2]nonane*?

I

3. A correct IUPAC name for the following compound is:

A) B) C) D) E)

Cl

4-propyl-5-chloro-3-heptanol 4-propyl-3-chloro-5-heptanol 4-(1-chloropropyl)-3-heptanol 5-chloro-4-propyl-3-heptanol 3-hydroxy-4-propyl-5-chloroheptane

Topic: Nomenclature

2.

A) B) C) D) E)

OH

A) B) C) D) E)

II

IV

2,5-Dimethyl-3-propylheptane 3,6-Dimethyl-5-propylheptane 6-Methyl-4-(1-methylethyl)octane 2-Methyl-3-(2-methylbutyl)hexane 3-Methyl-5-(1-methylethyl)octane

A) B) C) D) E)

III

V

I II III IV V

7. Select the systematic name for

A) B) C) D) E)

87

Cl

H

H

Cl

cis-1,3-Dichlorocyclopentane trans-1,4-Dichlorocyclopentane cis-1,2-Dichlorocyclopentane trans-1,3-Dichlorocyclopentane 1,1-Dichlorocyclopentane

88

Chapter 4

9. A) B) C) D) E)

Chapter 4

Which isomer of C5H10 would you expect to have the smallest heat of combustion*? Cyclopentane Methylcyclobutane 1,1-Dimethylcyclopropane cis-1,2-Dimethylcyclopropane trans-1,2-Dimethylcyclopropane

Topic: Nomenclature

18. A) B) C) D) E)

trans-1,2-Dibromocyclohexane is represented by structure(s): I II III II and III I and II

19. A) B) C) D) E)

cis-1,2-Dibromocyclohexane is represented by structure(s): I II III II and III I and II

12. What is the common name for this compound? Br

A) B) C) D) E)

Isobutyl bromide tert-Butyl bromide Butyl bromide sec-Butyl bromide Bromo-sec-butane

20. cis-1,3-Dibromocyclohexane is represented by structure(s):

H

3,6,7-trimethyl-4-bromo-1-octene 4-bromo-3-methyl-6-isopropyl-1-heptene 4-bromo-3,6,7-trimethyl-1-octene 4-bromo-6-isopropyl-3-methyl-1-heptene

Br

H

H Br

H

H

I

Br

Br

H

Br

H

II

III

89

H

Br H Br

Br

II

III

I II III II and III I and II CH3CHCH2!

21.

Use the following to answer questions 18-19: Br

H

I

A) B) C) D) E)

Br

H

Br

13. A correct IUPAC name for the following compound is:

A) B) C) D)

Br

H Br

CH2CH3 is:

A) B) C) D) E)

An IUPAC name for the group Isopentyl Isoamyl sec-Butylmethyl 2-Methylbutyl 2-Ethylpropyl

22. A) B) C) D) E)

The neopentyl group has the alternative name: 1,1-Dimethylpropyl 1,2-Dimethylpropyl 2,2-Dimethylpropyl 1-Methylbutyl 2-Methylbutyl

90

Chapter 4

23.

A) B) C) D) E)

Chapter 4

28. What is the correct IUPAC name for the following compound?

Br Cl is: The correct IUPAC name for 2-Bromo-4-chloro-4-isopropylpentane 4-Bromo-2-chloro-2-isopropylpentane 5-Bromo-3-chloro-2,3-dimethylhexane 2-Bromo-4-chloro-4,5-dimethylhexane 2-(2-Bromopropyl)-2-chloro-3-methylbutane

24. Which of the following is a correct name which corresponds to the common name tertpentyl alcohol*? A) 2,2-Dimethyl-1-propanol B) 2-Ethyl-2-propanol C) 2-Methyl-2-butanol D) 3-Methyl-1-butanol E) Methyl tert-butanol Topic: Nomenclature 25. The correct IUPAC name for the following compound is: OH

HO

A) B) C) D) E)

3-Hydroxymethylheptane 3-Hydroxymethylhexane 3-Methyloxyheptane 2-Ethyl-1-hexanol 2-Ethyl-1-heptanol

30. A) B) C) D) E)

Which of these is the common name for the 1,1-dimethylpropyl group*? tert-Butyl tert-Pentyl Isopentyl Neopentyl sec-Pentyl

31. Neglecting stereochemistry, which of these common group names is ambiguous, i.e., does not refer to one specific group*? A) Butyl B) sec-Butyl C) tert-Pentyl D) Neopentyl E) sec-Pentyl 32. What is the correct IUPAC name for the following compound? OH

A) B) C) D) E)

1-Hydroxy-3-sec-butylcyclopentane 3-sec-Butyl-1-cyclopentanol 1-sec-Butyl-3-cyclopentanol 4-sec-Butyl-1-cyclopentanol 3-Isobutyl-1-cyclopentanol

26. What is a correct name for the following compound?

A) B) C) D) E)

A) B) C) D) E)

5-Ethyl-3-methylhexanol 5-Ethyl-3-methyl-1-hexanol 2-Ethyl-4-methyl-6-hexanol 3,5-Dimethyl-7-heptanol 3,5-Dimethyl-1-heptanol

3-Isobutyl-2-methylheptane 3-sec-Butyl-2-methyloctane 5-Isobutyl-6-methylheptane 2-Ethyl-3-isopropyloctane 4-Isopropyl-3-methylnonane

91

92

Chapter 4

33. Isopentyl is the common name for which alkyl group? A) CH3CH2CH2CH

Chapter 4

36. What is the correct IUPAC name for the following compound?

CH3 B) CH3CH2CHCH2

HO

A) B) C) D) E)

CH3 C) CH3CHCH2CH2 CH3 D) CH3CH2CH

CH2CH3

E)

3-Hydroxymethyl-2-heptene 2-(1-methylethyl)-4-hexen-1-ol 5-(1-methylethyl)-2-hexen-6-ol 5-isopropyl-2,6-hexenol 2-(1-methylethyl)-4-hepten-1-ol

37. What is the correct IUPAC name for the following compound?

CH3

OH

CH3CCH2

F

CH3

A) B) C) D) E)

34.

A) B) C) D) E)

An IUPAC name for 3-Isobutyl-2,4-dimethylhexane 3-sec-Butyl-2,5-dimethylhexane 4-sec-Butyl-2,5-dimethylhexane 4-Isopropyl-2,5-dimethylheptane 4-Isopropyl-3,6-dimethylheptane

is:

5-Ethyl-3-fluorohexanol 5-Ethyl-3-fluoro-1-hexanol 2-Ethyl-4-fluoro-6-hexanol 3-fluoro-5-methyl-7-heptanol 3-fluoro-5-methyl-1-heptanol

38. A correct name for the following compound is: Cl

A) B) C) D) E)

3-chloro-8-methylbicyclo[4.3.0]nonane 8-Methyl-3-chlorobicyclo[4.3.1]nonane 3-Methyl-7-chlorobicyclo[4.3.0]nonane 3-Methyl-7-chlorobicyclo[4.3.1]decane 3-chloro-8-methyl[4.3.0]bicyclononane

35. An IUPAC name for the following compound is:

A) B) C) D) E)

4-Isobutyl-3,4-dimethylheptane 4-sec-Butyl-2,4-dimethylheptane 2,4,5-Trimethyl-4-propylheptane 3,4,6-Trimethyl-4-propylheptane 4-Isobutyl-4,5-dimethylheptane

93

94

Chapter 4

Chapter 4

Topic: Conformational Analysis

Topic: Ring Strain 41-47

40. The least stable conformation of butane is: H H3C

H

H3C

H H

I

H CH3 CH3

H H

CH3

I

H3C

II

H H

II

III CH3

CH3

H

CH3

H

IV

CH3

A) B) C) D) E)

H

H

H

IV

V

I II III IV V

44. Which cycloalkane has the lowest heat of combustion per CH2 group*?

The preferred conformation of cis-3-tert-butyl-1-methylcyclohexane is the one in which the tert-butyl group is axial and the methyl group is equatorial. the methyl group is axial and the tert-butyl group is equatorial. both groups are axial. both groups are equatorial. the molecule exists in a boat conformation.

42. What structure represents the most stable conformation of cis-1,3-dimethylcyclohexane? CH3

H

CH3

H

H

CH3 CH3

H3C

H

H3C

H

I

II

III H

CH3 H3C

CH3 H3C

H

H

IV

II

IV

A) B) C) D) E)

III

V

I II III IV V

H

H

A) B) C) D) E)

V

I II III IV V

I

41. A) B) C) D) E)

III

H H

H

A) B) C) D) E)

43. Which cycloalkane has the largest heat of combustion per CH2 group*? H

H H

V

45. A) B) C) D) E)

Which isomer would have the largest heat of combustion*? Propylcyclopropane Ethylcyclobutane Methylcyclopentane Cyclohexane Since they are all isomers, all would have the same heat of combustion.

I II III IV V

95

96

Chapter 4

Chapter 4

46. A) B) C) D) E)

Which is the most stable conformation of cyclohexane? Chair Twist Boat One-half chair Staggered

47. A) B) C) D) E)

Which cycloalkane has the greatest ring strain? Cyclopropane Cyclobutane Cyclopentane Cyclohexane Cycloheptane

50. The most stable conformation of 2,3-dibromobutane, viewed through the C-2—C-3 bond : CH3 Br

H

Br

H

H

H3C

H

H3C

CH3 CH3

H

I

A) B) C) D) E)

H3C

II

CH3

H CH3

H

CH3

H

H

H

CH3

H

CH3 H

H

H

H

III

IV

V

I II III IV V

H CH3

V

I II III IV V

51. The most stable conformation of 3-bromo-2-methylpentane, viewed through the C-3—C-4 bond (i.e., C-3 in the front, C-4 in the back): CH3 Br H

49. The most stable conformation of 1,2-dibromoethane is: H Br

H H

I

H

H H

H

Br

A) B) C) D) E)

H3C

H Br

H H

Br

H

H

IV

H H H H

III Br

Br

A) B) C) D) E)

CH3

II

H3C

48. The most stable conformation of butane is:

Br

Br H

I

Topic: Conformational Analysis H

H3C Br Br

H3C H3C

CH3

H3C

H

H H

H

H

H

H

I

Br Br

H

Br

Br

Br

H

H

II

I II III IV V

H

H

H

III

IV

V

H CH3 CH(CH3)2

H H

H CH(CH3)2 H

H

H

CH3 H

A) B) C) D) E)

CH3 CH(CH3)2

CH3 Br

CH(CH3)2

H

Br

III

CH3 CH2CH3

V

IV

97

H

II Br

Br Br

H H

H Br

H

Br H

H

I II III IV V

98

Chapter 4

Chapter 4

52. The most stable conformation of 3-bromo-2-methylpentane, viewed through the C-2—C-3 bond (i.e., C-2 in the front, C-3 in the back): H H

CH3

Br

H

Br H

CH3

H CH3 CH2CH3

H H3C

CH3

I

CH3 CH(CH3)2

H

Br

CH2CH3

H

H

CH3

55. The most stable conformation of cis-1-tert-butyl-2-methylcyclohexane is the one in which: A) the tert-butyl group is axial and the methyl group is equatorial. B) the methyl group is axial and the tert-butyl group is equatorial. C) both groups are axial. D) both groups are equatorial. E) the twist boat conformation is adopted.

CH3 CH2CH3

H

IV

V

I II III IV V

53. The most stable conformation of 2,3-dimethylpentane, viewed through the C-2—C-3 bond (i.e., C-2 in the front, C-3 in the back): CH3

CH3

CH3 H

H

CH3

H

CH2CH3 CH3

CH2CH3 H

H H3C

CH3

H

H CH(CH3)2

III CH3

CH3 CH3

H H3CH2C

H

H

H3C H

CH3

CH3 CH(CH3)2

V

IV

A) B) C) D) E)

H

II

I

Which cycloalkane has the least ring strain? Cyclopropane Cyclobutane Cyclopentane Cyclohexane Cycloheptane

Topic: Conformational Analysis

CH3

Br

54. A) B) C) D) E)

III

II CH3

A) B) C) D) E)

Br

H

Topic: Ring Strain

I II III IV V

99

56. The most stable conformation of trans-1-tert-butyl-2-methylcyclohexane is the one in which: A) the tert-butyl group is axial and the methyl group is equatorial. B) the methyl group is axial and the tert-butyl group is equatorial. C) both groups are axial. D) both groups are equatorial. E) the molecule is in the half chair conformation. 57. The most stable conformation of trans-1-tert-butyl-3-methylcyclohexane is the one in which: A) the tert-butyl group is axial and the methyl group is equatorial. B) the methyl group is axial and the tert-butyl group is equatorial. C) both groups are axial. D) both groups are equatorial. E) the twist boat conformation is adopted. 58. A) B) C) D) E)

In the most stable conformation of cis-1,4-dimethylcyclohexane, the methyl groups are: one axial, one equatorial. both axial. both equatorial. alternating between being both axial and both equatorial. None of the above

100

Chapter 4

H H

OH

H

62. Consider the graph below, which is a plot of the relative energies of the various conformations of hexane, viewed through the C2-C3 bond. The conformations corresponding to the 60o and 300o are: Relative energy

59. The most stable conformation for 1,2-ethanediol (ethylene glycol) is shown below. It is the most stable conformation because:

Chapter 4

OH H

A) B) C) D) E)

this corresponds to an anti conformation. in general, gauche conformations possess the minimum energy. it is stabilized by intramolecular hydrogen bonding. it is a staggered conformation. it has the highest energy of all the possibilities.

0o

60. The graph below is a plot of the relative energies of the various conformations of:

60

o

o

120 180

o

240

o

300

o

360

o

63. Consider the graph below, which is a plot of the relative energies of the various conformations of 2,3-dimethylbutane, viewed through the C2-C3 bond. The conformations corresponding to the 120o and 240o are:

Angle of rotation

A) B) C) D) E)

Ethane Propane Chloroethane 1-Chloropropane (C1-C2 rotation) Butane (C1-C2 rotation)

Relative energy

61. The graph below is a plot of the relative energies of the various conformations of:

0

o

0o

60

o

o

120 180

o

240

o

300

o

360

A) B) C) D) E)

o

Angle of rotation

A) B) C) D) E)

Eclipsed Staggered, and gauche Staggered and anti More stable than the conformation at 180o None of the above

Relative energy

o

Angle of rotation

A) B) C) D) E)

Relative energy 0

60 o 120 o 180 o 240 o 300 o 360 o

2-chloropropane 1,3-dichloropropane 2-methylpropane Butane (C1-C2 rotation) Butane (C2-C3 rotation) Ans: E

101

60o 120o 180o 240o 300o 360o

Angle of rotation Eclipsed, more stable than the conformation at 0o Eclipsed, more stable than the conformation at 180o Staggered, more stable than the conformation at 0o Staggered, less stable than the conformation at 180o Two of the above are true

102

Chapter 4

Chapter 4

Topic: Conformational Analysis

67. Which of the following can be described as trans isomers?

64. Which conformation of trans-1-isopropyl-3-methylcyclohexane would be present in greatest amount at equilibrium? A) The conformation with the methyl group equatorial and the isopropyl group axial B) The conformation with the methyl group axial and the isopropyl group equatorial C) The conformation with both groups axial D) The conformation with both groups equatorial E) The twist boat conformation. 65. Which conformation represents the most stable conformation of trans-1-bromo-4methylcyclohexane? CH3

Br

Br

Br

Br CH3

I

A) B) C) D) E)

II

CH3

Br

HO

Cl

CH3 CH2CH3

HO F

CH3

I A) B) C) D) E)

CH3

Br

II

III

IV

V

I II, V III, IV I, III and IV None of the above are trans isomers.

Topic: Conformational Analysis

H3C

Br

CH3

IV

III

68. Which of the following will have the same energy after undergoing ring flip?

V

I II III IV V

OH

HO

Cl

Br CH3

I

Topic: Cis-Trans Isomers

CH3

CH2CH3 CH2CH3

HO

F

II

III

A) B) C) D) E)

I II III IV V.

69. A) B) C) D) E)

The least stable conformation of cyclohexane is the: boat. twist boat. chair. half-chair. twist chair.

IV

V

66. Which of the following can be described as cis isomers? Br

HO

Cl

Br CH3

I A) B) C) D) E)

II

CH3

CH3 CH2CH3

HO

F

III

I II, V III, IV I, III and IV None of the above are cis isomers.

IV

V