Deck 8: Nucleophilic Substitution

Question 1

Which of the following cannot act as a nucleophile?

A) $\mathrm{NH}_{3}$
B) $\mathrm{H}_{2} \mathrm{O}$
C) $\overline{\mathrm{I}}$
D) $\mathrm{CH}_{4}$

Answer 1

$\mathrm{CH}_{4}$

Question 2

Which of the following undergoes a substitution reaction with sodium cyanide in DMSO at the fastest rate?

A) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{~F}$
B) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Cl}$
C) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Br}$
D) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{I}$

Answer 2

$\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{I}$

Question 3

The rate law for the following reaction is

A) rate $=\mathrm{k}\left[\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Cl}\right]$ .
B) rate $=\mathrm{k}\left[\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Cl}\right][\mathrm{NaCN}]$ .
C) rate $=\mathrm{k}\left[\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Cl}\right][\mathrm{NaCN}]^{2}$ .
D) rate $=\mathrm{k}[\mathrm{NaCN}]$ .

Answer 3

rate $=\mathrm{k}\left[\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Cl}\right][\mathrm{NaCN}]$ .

Question 4

Identify the major product(s) in the reaction of (R)-2-bromopentane with sodium cyanide in DMSO?

A) (R)-2-cyanopentane
B) (S)-2-cyanopentane
C) racemic mixture of 2-cyanopentane
D) trans-2-pentene

Question 5

Which of the following reacts fastest with methanol by the $\mathrm{S}_{\mathrm{N}} 1$ mechanism?

A)

B)

C)

D)

Question 6

Considering the $\mathrm{S}_{\mathrm{N}} 1, \mathrm{~S}_{\mathrm{N}} 2$ , E1, and $\mathrm{E} 2$ mechanisms, the energy diagram shown below corresponds to

A) only the $\mathrm{S}_{\mathrm{N}} 1$ mechanism.
B) only the $S_{N} 2$ mechanism.
C) both the $\mathrm{S}_{\mathrm{N}} 1$ and $\mathrm{E} 1$ mechanisms.
D) both the $\mathrm{S}_{\mathrm{N}} 2$ and $\mathrm{E} 2$ mechanisms.

Question 7

Identify the substitution product(s) in the following reaction.

A)

B)

C)

D) a mixture of $A$ and $B$

Question 8

Which sequence of reactions below gives the highest yield of ethyl isopropyl ether?

A)

B)

C)

D)

Question 9

How would you synthesize the following compound starting with optically pure (R) or (S)-2-butanol?

A) (1) (R)-2-butanol $+\mathrm{TsCl}$ (2) NaCN/DMSO
B) (1) (S)-2-butanol + TsCl (2) NaCN/DMSO
C) (1) (S)-2-butanol $+\mathrm{H}_{2} \mathrm{SO}_{4}$ (heat) (2) $\mathrm{HBr}$ (3) NaCN/DMSO
D) (R)-2-butanol + NaCN/DMSO

Question 10

The species shown below represents the transition state for the

A) reaction of 1-propanol with $\mathrm{HBr}$ .
B) reaction of 1-bromopropane with $\mathrm{OH}^{-}$ .
C) addition of $\mathrm{HOBr}$ to 1-propene.
D) addition of $\mathrm{HBr}$ to propene with peroxides.

Question 11

Which of the following is the double substitution product of the reaction below?

A)

B)

C)

D)

Question 12

Starting with 1-methylcyclohexene, which of the following reaction sequences is the best synthesis of the azide shown below?

A)
B)
C)
D)

Question 13

Which of the following mechanistic steps is the most likely route for the formation of the cyclic ether shown?

A)

B)

C)

D)

Question 14

What major product, if any, is expected here?

A)
B)
C)
D) no reaction occurs