Chemistry Chapter 12 2 Which of the following alkenes cannot be converted into an alkyne

41. Identify the changes that must occur in transforming cis-2-butene into 2-butanol:

A) only the identity of the functional group(s) must change

B) only the carbon skeleton must change

C) only the location of the functional group(s) must change

D) only the identity and location of the functional group(s) must change

E) both the carbon skeleton and the identity of the functional group(s)

must change

42. Propose an efficient synthesis of 1-butene from propyne:

43. The following sequence of reactions transforms acetylene into a compound with

an altered carbon skeleton (compound 1), and from that into a compound in which

the functional group has been changed (compound 2). Identify compounds 1 and

2:

1) NaNH2

2) bromoethane

11) H2, Ni2B

2) BH3-THF

3) H2O2, NaOH

OH

2

III III IV

VVI VII VIII

A) Compound 1 = I; Compound 2 = III

B) Compound 1 = II; Compound 2 = III

C) Compound 1 = VI; Compound 2 = IV

D) Compound 1 = II; Compound 2 = IV

E) Compound 1 = II; Compound 2 = V

F) Compound 1 = VII; Compound 2 = VIII

44. Which of the following sequences efficiently converts 2-methylpropene and

sodium acetylide into 3-methylbutanal?

H

O

3-methylbutanal

??

A) 1) HBr; 2) NaCCH; 3) O3; 4) H2O

B) 1) HBr; 2) NaCCH; 3) O3; 4) DMS

C) 1) HBr, ROOR; 2) NaCCH; 3) O3; 4) H2O

D) 1) HBr, ROOR; 2) NaCCH; 3) H2/Ni2B 3) O3; 4) DMS

E) 1) NaCCH; 2) H2/Ni2B; 3) O3; 4) DMS

45. Which of the following sequences most efficiently converts 3-methyl-1-pentene

into 3-bromo-3-methylpentane?

A) 1) HBr; 2) NaOH; 3) HBr

B) 1) Br2, h; 2) H2, Pt

C) 1) H2, Pt; 2) Br2, h

D) 1) NBS, h; 2) H2, Pt

E) 1) HBr, ROOR; 2) NaOH; 3) HBr

46. Propose a strategy to carry out the following transformation:

?? O

OH

47. Propose an efficient method of converting 3-methyl-2-butanol into 3-methyl-1-

butanol.

48. Propose an efficient method of converting 3-methyl-1-butanol into 3-methyl-2-

butanol.

49. Which of the following alkenes cannot be converted into an alkyne by reaction

with bromine followed by excess sodium amide and then with water?

III III IV

A) I

B) II

C) III

D) IV

E) III and IV

50. Which of the following provides an efficient method of converting 3-bromo-2-

methyl-1-butene into 2-methyl-2-butene?

A) 1) NaOH; 2) H2, Pt

B) 1) H2, Pt; 2) NaOEt

C) 1) H2, Pt; 2) xs NaNH2

D) 1) H2, Ni2B; 2) KOtBu

E) 1) H2, Pt; 2) KOtBu

51. Which order of alterations would most effectively transform trans-2-butene into

1-butene?

A) convert to the dibromoalkane, then to the terminal alkyne, then to the

terminal alkene

B) convert to an alcohol, then to a terminal alkyne, finally to the terminal

alkene

C) convert to the terminal alkene in one step

D) shorten the chain by two carbons, then add a two-carbon alkene to the

end

E) convert to an alkane, then to a terminal alkyne, and finally to a terminal

alkene

52. What is the minimum number of steps required to convert 2-methylpropane into

2-methylpropene?

A) 1

B) 2

C) 3

D) 4

E) 5

53. What is the minimum number of steps required to convert 2-methylpropane into

1-bromo-2-methyl-2-propanol?

A) 1

B) 2

C) 3

D) 4

E) 5

54. Propose an efficient method of completing the following transformation:

Br

??

HO

OH

+ En

55. Propose an efficient method of completing the following transformation:

??

S

56. Propose an efficient method of completing the following transformation:

Br

??

S

57. Propose an efficient method of completing the following transformation:

OH

O

??

58. Propose an efficient method of completing the following transformation:

Br

CHO

??

59. Demonstrate your understanding of retrosynthetic synthesis and determine which

compound(s) could lead immediately to the alkene shown below:

??

Br

I II III IV

A) I

B) II

C) III

D) IV

E) I and IV

F) I, III, and IV

60. Using retrosynthetic synthesis, determine which compound(s) could lead

immediately to the alcohol shown below:

OH

??

I II III IV

A) I

B) II

C) III

D) IV

E) I and II

F) I, II, and IV

61. Using retrosynthetic synthesis, determine which compound(s) could lead

immediately to the alkyne shown below:

??

Br

I II III IV

Br Br

Br

A) I

B) II

C) III

D) IV

E) I and II

F) I, II, and IV

62. Using the concept of retrosynthetic synthesis, determine which compound(s)

could lead immediately to the alkane shown below:

??

I II III IV

Br OH

A) II and III

B) I and IV

C) I

D) II

E) III

F) IV

63. Using the concept of retrosynthetic synthesis, determine which compound(s)

could lead immediately to the bromoalkene shown below:

Br ??

Br Br

OH

I II III IV

A) I and III

B) I and IV

C) I

D) II

E) III

F) IV

64. Show that you understand the concept of retrosynthetic analysis by working

backwards two steps in the synthesis below. Identify possible combinations of A

and B that could lead to the alkyl halide (C):

Br

BA

C

Br

I II III IV

VVI VII VIII

OH

Br

Cl

A) B = I and A = VI

B) B = VI and A = I

C) B = III and A = VII

D) B = IV and A = VII

E) B = I and A = III

F) B = V and A = VIII

65. Show that you understand the concept of retrosynthetic analysis by working

backwards two steps in the synthesis below. Identify possible combinations of A

and B that can lead to the alkyne (C):

BA

C

Br

I II III IV

VVI VII VIII

OH

Br

Cl

Br

A) B = I and A = VI

B) B = VI and A = I

C) B = III and A = VII

D) B = IV and A = VII

E) B = I and A = III

F) B = VI and A = VIII

66. Show that you understand the concept of retrosynthetic analysis by working

backwards two steps in the synthesis below. Identify possible combinations of A

and B that can lead to the alcohol (C):

BA

C

Br

I II III IV

VVI VII VIII

Br

Cl

Br

OH

Br

A) B = I and A = VI

B) B = VI and A = I

C) B = III and A = VII

D) B = IV and A = VII

E) B = I and A = III

F) B = VIII and A = V

67. Show that you understand the concept of retrosynthetic analysis by working

backwards two steps in the synthesis below. Identify possible combinations of A

and B that can lead to the compound shown (C):