Organic chemistry with biological applications

John E. McMurry

Chapter 12

Organohalides: Nucleophilic Substitutions and Eliminations - all with Video Answers

Educators

Chapter Questions

Problem 1

Give IUPAC names for the following alkyl halides:
(a) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{I}$
(b)
(c)
(d)
(e)
(f)

Vasu Makani

Vasu Makani

Numerade Educator

Problem 2

Draw structures corresponding to the following IUPAC names:
(a) 2 -Chloro-3,3-dimethylhexane
(b) 3,3 -Dichloro-2-methylhexane
(c) 3-Bromo-3-ethylpentane
(d) 1,1 -Dibromo-4-isopropylcyclohexane
(e) 4 -sec-Butyl-2-chlorononane
(f) 1,1 -Dibromo-4-tert-butylcyclohexane

David Taylor

Numerade Educator

Problem 3

Draw three resonance forms for the cyclohexadienyl radical.

Ian Kaigh

Numerade Educator

Problem 4

The major product of the reaction of methylenecyclohexane with $N$ -bromosuccinimide is 1 -(bromomethyl)cyclohexene. Explain.

Matthew Lueckheide

Matthew Lueckheide

Numerade Educator

Problem 5

What products would you expect from reaction of the following alkenes with NBS? If more than one product is formed, show the structures of all.
(a)
(b)

Lauren Irwin

Numerade Educator

Problem 6

How would you prepare the following alkyl halides from the corresponding alcohols?
(a)
(b)
(c)
(d)

Tom Rutherford

Numerade Educator

Problem 7

How strong a base would you expect a Grignard reagent to be? Look at Table 8.3 on page 257 , and then predict whether the following reactions will occur as written. (The $\mathrm{pK}_{\mathrm{a}}$ of $\mathrm{NH}_{3}$ is 35.)
(a) $\mathrm{CH}_{3} \mathrm{MgBr}+\mathrm{H}-\mathrm{C} \equiv \mathrm{C}-\mathrm{H} \rightarrow \mathrm{CH}_{4}+\mathrm{H}-\mathrm{C} \equiv \mathrm{C}-\mathrm{MgBr}$
(b) $\mathrm{CH}_{3} \mathrm{MgBr}+\mathrm{NH}_{3} \rightarrow \mathrm{CH}_{4}+\mathrm{H}_{2} \mathrm{~N}-\mathrm{MgBr}$

Tom Rutherford

Numerade Educator

Problem 8

How might you replace a halogen substituent by a deuterium atom if you wanted to prepare a deuterated compound?

Ronald Prasad

Numerade Educator

Problem 9

How would you carry out the following transformations using an organocopper coupling reaction? More than one step is needed in each case.
(a)
(b)
(c)

Tom Rutherford

Numerade Educator

Problem 10

What product would you expect to obtain from a nucleophilic substitution reaction of $(S)-2$ -bromohexane with acetate ion, $\mathrm{CH}_{3} \mathrm{CO}_{2}^{-}$ ? Assume that inversion of configuration occurs, and show the stereochemistry of both reactant and product.

Alma Victoriano

Alma Victoriano

North Carolina State University

Problem 11

What product would you expect to obtain from $\mathrm{S}_{\mathrm{N}} 2$ reaction of $\mathrm{OH}^{-}$ with ( $R$ )-2-bromobutane? Show the stereochemistry of both reactant and product.

Osman Elomda

Numerade Educator

Problem 12

Assign configuration to the following substance, and draw the structure of the product that would result on nucleophilic substitution reaction with $\mathrm{HS}^{-}($ red-brown $=\mathrm{Br})$.

Anupa Sharad Medhekar

Anupa Sharad Medhekar

Numerade Educator

Problem 13

What product would you expect from $\mathrm{S}_{\mathrm{N}}$ 2 reaction of 1 -bromobutane with each of the following?
(a) NaI
(b) KOH
(c) $\mathrm{H}-\mathrm{C} \equiv \mathrm{C}-\mathrm{Li}$
(d) $\mathrm{NH}_{3}$

Alma Victoriano

Alma Victoriano

North Carolina State University

Problem 14

Which substance in each of the following pairs is more reactive as a nucleophile? Explain.
(a) $\left(\mathrm{CH}_{3}\right)_{2} \mathrm{~N}^{-}$ or $\left(\mathrm{CH}_{3}\right)_{2} \mathrm{NH}$
(b) $\left(\mathrm{CH}_{3}\right)_{3} \mathrm{~B}$ or $\left(\mathrm{CH}_{3}\right)_{3} \mathrm{~N}$
(c) $\mathrm{H}_{2} \mathrm{O}$ or $\mathrm{H}_{2} \mathrm{~S}$

Alma Victoriano

Alma Victoriano

North Carolina State University

Problem 15

Rank the following compounds in order of their expected reactivity toward $\mathrm{S}_{\mathrm{N}} 2$ reaction:
$$
\mathrm{CH}_{3} \mathrm{Cl}, \mathrm{CH}_{3} \mathrm{OTos}, \mathrm{CH}_{3} \mathrm{NH}_{2},\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CHCl}
$$

Alma Victoriano

Alma Victoriano

North Carolina State University

Problem 16

Organic solvents such as ether and chloroform are neither protic nor strongly polar. What effect would you expect these solvents to have on the reactivity of a nucleophile in $\mathrm{S}_{\mathrm{N}}$ 2 reactions?

Alma Victoriano

Alma Victoriano

North Carolina State University

Problem 17

What product(s) would you expect from reaction of ( $S$ )-3-chloro-3-methyloctane with acetic acid? Show the stereochemistry of both reactant and product.

Alma Victoriano

Alma Victoriano

North Carolina State University

Problem 18

Among the many examples of $\mathrm{S}_{\mathrm{N}} 1$ reactions that occur with incomplete racemization, the optically pure tosylate of 2,2 -dimethyl-1-phenylpropan-1-ol $\left([\alpha]_{\mathrm{D}}=-30.3\right.$ ) gives the corresponding acetate $\left([\alpha]_{\mathrm{D}}=+5.3\right)$ when heated in acetic acid. If complete inversion had occurred, the optically pure acetate would have had $[\alpha]_{\mathrm{D}}=+53.6 .$ What percentage racemization and what percentage inversion occurred in this reaction?

Osman Elomda

Numerade Educator

Problem 19

Assign configuration to the following substrate, and show the stereochemistry and identity of the product you would obtain by $\mathrm{S}_{\mathrm{N}} 1$ reaction with water (red brown $=\mathrm{Br}$ ):

Osman Elomda

Numerade Educator

Problem 20

Rank the following substances in order of their expected $S_{N} 1$ reactivity:

Alma Victoriano

Alma Victoriano

North Carolina State University

Problem 21

3-Bromobut-1-ene and 1-bromobut-2-ene undergo $\mathrm{S}_{\mathrm{N}}$ 1 reaction at nearly the same rate even though one is a secondary halide and the other is primary. Explain.

Alma Victoriano

Alma Victoriano

North Carolina State University

Problem 22

Predict whether each of the following substitution reactions is likely to be $\mathrm{S}_{\mathrm{N}} 1$ or $\mathrm{S}_{\mathrm{N}} 2:$
(a)
(b)

Osman Elomda

Numerade Educator

Problem 23

Review the mechanism of geraniol biosynthesis shown in Figure $12.18,$ and propose a mechanism for the biosynthesis of limonene from linalyl diphosphate. What kind of reaction is occurring?

Lainey Roebuck

Numerade Educator

Problem 24

Ignoring double-bond stereochemistry, what products would you expect from elimination reactions of the following alkyl halides? Which product will be major in each case?
(a)
(b)
(c)

Anupa Sharad Medhekar

Anupa Sharad Medhekar

Numerade Educator

Problem 25

What alkyl halides might the following alkenes have been made from?
(a)
(b)

Osman Elomda

Numerade Educator

Problem 26

What stereochemistry do you expect for the alkene obtained by E2 elimination of $(1 R, 2 R)-1,2$ -dibromo-1,2-diphenylethane? Draw a Newman projection of the reacting conformation.

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 27

The following alkyl halide undergoes E2 elimination on treatment with KOH to give a mixture of two alkenes, one monosubstituted and one trisubstituted. What stereochemistry do you expect for the trisubstituted alkene? (Red-brown $=\mathrm{Br}$.)

Lainey Roebuck

Numerade Educator

Problem 28

Which would you expect to undergo E2 elimination faster, trans-1-bromo4-tert-butylcyclohexane or cis-1-bromo-4-tert-butylcyclohexane? Draw each molecule in its more stable chair conformation, and explain your answer.

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 29

Tell whether each of the following reactions is likely to be $\mathrm{S}_{\mathrm{N}} 1, \mathrm{~S}_{\mathrm{N}} 2, \mathrm{E} 1, \mathrm{E} 1 \mathrm{cB},$ or E2:
(a)
(b)
(c)
(d)

Osman Elomda

Numerade Educator

Problem 30

Give IUPAC names for the following alkyl halides (green $=\mathrm{Cl}$ ):
(a)
(b)

Tom Rutherford

Numerade Educator

Problem 31

Show the product(s) of reaction of the following alkenes with NBS:
(a)
(b)

Lauren Irwin

Numerade Educator

Problem 32

The following alkyl bromide can be prepared by reaction of the alcohol
(S)-pentan-2-ol with $\mathrm{PBr}_{3}$. Name the compound, assign $(R)$ or $(S)$ stereochemistry, and tell whether the reaction of the alcohol occurs with retention or inversion of configuration (red-brown $=\mathrm{Br}$ ).

Tom Rutherford

Numerade Educator

Problem 33

Write the product you would expect from reaction of each of the following alkyl chlorides with
(i) $\mathrm{Na}^{+}-\mathrm{SCH}_{3}$ and
(ii) $\mathrm{Na}^{+}-\mathrm{OH}$ :
(a)
(b)
(c)

Lainey Roebuck

Numerade Educator

Problem 34

From what alkyl bromide was the following alkyl acetate made by $\mathrm{S}_{\mathrm{N}}$ 2 reaction? Write the reaction, showing the stereochemistry.

Lainey Roebuck

Numerade Educator

Problem 35

Assign $R$ or $S$ configuration to the following chloro alcohol, write the product from $\mathrm{S}_{\mathrm{N}}$ 2 reaction with $\mathrm{NaCN}$, and assign $R$ or $S$ configuration to the product:

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 36

Draw the structure and assign $Z$ or $E$ stereochemistry to the product you expect from $\mathrm{E} 2$ reaction of the following molecule with $\mathrm{NaOH}$ :

Osman Elomda

Numerade Educator

Problem 37

Name the following alkyl halides:
(a)
(b)
(c)
(d)
(e)

rb

Rabia Bibi

Numerade Educator

Problem 38

Draw structures corresponding to the following IUPAC names:
(a) 2,3 -Dichloro-4-methylhexane
(b) 4 -Bromo-4-ethyl-2-methylhexane
(c) 3 -Iodo- 2,2,4,4 -tetramethylpentane
(d) cis-1-Bromo-2-ethylcyclopentane

David Taylor

Numerade Educator

Problem 39

Draw and name all monochloro derivatives of 2 -methylbutane. Which are chiral?

Tom Rutherford

Numerade Educator

Problem 40

How would you prepare the following compounds, starting with cyclopentene and any other reagents needed?
(a) Chlorocyclopentane
(b) Methylcyclopentane
(c) 3-Bromocyclopentene
(d) Cyclopentanol
(e) Cyclopentylcyclopentane
(f) Cyclopenta-1,3-diene

Tom Rutherford

Numerade Educator

Problem 41

What product(s) would you expect from the reaction of 1 -methylcyclohexene with NBS?

Niamat Khuda

Numerade Educator

Problem 42

Predict the product(s) of the following reactions:

Grigoriy Sereda

Grigoriy Sereda

Numerade Educator

Problem 43

None of the following reactions take place as written. What is wrong with each?

Ian Kaigh

Numerade Educator

Problem 44

Identify the reagents $a-c$ in the following scheme:

Madi Sousa

Numerade Educator

Problem 45

Which compound in each of the following pairs will react faster in an $\mathrm{S}_{\mathrm{N}} 2$ reaction with $\mathrm{OH}^{-} ?$
(a) $\mathrm{CH}_{3} \mathrm{Br}$ or $\mathrm{CH}_{3} \mathrm{I}$
(b) $\mathrm{CH}_{3} \mathrm{CH}_{2}$ I in ethanol or in dimethyl sulfoxide
(c) $\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CCl}$ or $\mathrm{CH}_{3} \mathrm{Cl}$
(d) $\mathrm{H}_{2} \mathrm{C}=\mathrm{CHBr}$ or $\mathrm{H}_{2} \mathrm{C}=\mathrm{CHCH}_{2} \mathrm{Br}$

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 46

What effect would you expect the following changes to have on the rate of the $S_{N} 2$ reaction of 1 -iodo- 2 -methylbutane with cyanide ion?
(a) The CN $^{-}$ concentration is halved, and the 1 -iodo-2-methylbutane concentration is doubled.
(b) Both the CN $^{-}$ and the 1 -iodo-2-methylbutane concentrations are tripled.

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 47

What effect would you expect the following changes to have on the rate of the reaction of ethanol with 2 -iodo-2-methylbutane?
(a) The concentration of the halide is tripled.
(b) The concentration of the ethanol is halved by adding diethyl ether as an inert solvent.

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 48

How might you prepare each of the following molecules using a nucleophilic substitution reaction at some step?
(a) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CN}$
(b) $\mathrm{H}_{3} \mathrm{C}-\mathrm{O}-\mathrm{C}\left(\mathrm{CH}_{3}\right)_{3}$
(c) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{NH}_{2}$

Lainey Roebuck

Numerade Educator

Problem 49

Which reaction in each of the following pairs would you expect to be faster?
(a) The $S_{N} 2$ displacement by $I^{-}$ on $\mathrm{CH}_{3} \mathrm{Cl}$ or on $\mathrm{CH}_{3} \mathrm{OTos}$
(b) The $S_{N} 2$ displacement by $\mathrm{CH}_{3} \mathrm{CO}_{2}-$ on bromoethane or on bromocyclohexane
(c) The $S_{N} 2$ displacement on 2 -bromopropane by $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{O}^{-}$ or by CN $^{-}$
(d) The $S_{N} 2$ displacement by $H S^{-}$ on bromomethane in toluene or in acetonitrile

Lainey Roebuck

Numerade Educator

Problem 50

The following Walden cycle has been carried out. Explain the results, and indicate where Walden inversion is occurring.

Lainey Roebuck

Numerade Educator

Problem 51

Order each of the following sets of compounds with respect to $\mathrm{S}_{\mathrm{N}} 1$ reactivity:
(a)
(b)
(c)

Lainey Roebuck

Numerade Educator

Problem 52

Order each of the following sets of compounds with respect to $\mathrm{S}_{\mathrm{N}}$ 2 reactivity:
(a)
(b)
(c)

Lainey Roebuck

Numerade Educator

Problem 53

Predict the product and give the stereochemistry resulting from reaction of each of the following nucleophiles with $(R)-2$ -bromooctane:
(a) $^{-} \mathrm{CN}$
(b) $\mathrm{CH}_{3} \mathrm{CO}_{2}^{-}$
(c) $\mathrm{CH}_{3} \mathrm{~S}^{-}$

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 54

( $R$ )-2-Bromooctane undergoes racemization to give $(\pm)-2$ -bromooctane when treated with NaBr in dimethyl sulfoxide. Explain.

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 55

Reaction of the following $S$ tosylate with cyanide ion yields a nitrile product that also has $S$ stereochemistry. Explain.

Lainey Roebuck

Numerade Educator

Problem 56

The $S_{N} 2$ reaction can occur intramolecularly (within the same molecule). What product would you expect from treatment of 4 -bromobutan-1-ol with base?

Alma Victoriano

Alma Victoriano

North Carolina State University

Problem 57

Propose structures for compounds that fit the following descriptions:
(a) An alkyl halide that gives a mixture of three alkenes on E2 reaction
(b) An organic halide that will not undergo nucleophilic substitution
(c) An alkyl halide that gives the non-Zaitsev product on E2 reaction
(d) An alcohol that reacts rapidly with $\mathrm{HCl}$ at $0^{\circ} \mathrm{C}$

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 58

1-Chloro-1,2-diphenylethane can undergo E2 elimination to give either cis- or trans-1,2-diphenylethylene (stilbene). Draw Newman projections of the reactive conformations leading to both possible products, and suggest a reason why the trans alkene is the major product.

Lainey Roebuck

Numerade Educator

Problem 59

Predict the major alkene product of the following E1 reaction:

Alexander Cheng

Alexander Cheng

Numerade Educator

Problem 60

The tosylate of $(2 R, 3 S)-3$ -phenylbutan-2-ol undergoes E2 elimination on treatment with sodium ethoxide to yield (Z)-2-phenylbut-2-ene. Explain, using Newman projections.

Lainey Roebuck

Numerade Educator

Problem 61

In light of your answer to Problem $12.60,$ which alkene, $E$ or $Z$, would you expect from an E2 reaction on the tosylate of $(2 R, 3 R)-3$ -phenylbutan-2-ol? Which alkene would result from E2 reaction on the $(2 S, 3 R)$ and $(2 S, 3 S)$ tosylates? Explain.

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 62

How can you explain the fact that trans-1-bromo-2-methylcyclohexane yields the non-Zaitsev elimination product 3 -methylcyclohexene on treatment with base?

Anupa Sharad Medhekar

Anupa Sharad Medhekar

Numerade Educator

Problem 63

There are eight diastereomers of 1,2,3,4,5,6 -hexachlorocyclohexane. Draw each in its more stable chair conformation. One isomer loses HCl in an E2 reaction nearly 1000 times more slowly than the others. Which isomer reacts so slowly, and why?

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 64

The antidepressant fluoxetine, marketed as Prozac, can be prepared by a sequence of steps that involves the substitution reaction of an alkyl chloride with a phenol, using a base to convert the phenol into its phenoxide anion.
(a) Identify the nucleophile and electrophile in the reaction.
(b) The rate of the substitution reaction depends on concentrations of both the alkyl chloride and phenol. Is this an $\mathrm{S}_{\mathrm{N}} 1$ or an $\mathrm{S}_{\mathrm{N}}$ 2 reaction?
(c) The physiologically active enantiomer of fluoxetine has ( $S$ ) stereochemistry. Based on your answer in part (b), draw the structure of the alkyl chloride showing the correct stereochemistry.

Mikayla Stephens

Mikayla Stephens

Numerade Educator

Problem 65

The following reactions are unlikely to occur as written. Tell what is wrong with each, and predict the actual product.

Prashant Bana

Numerade Educator

Problem 66

Arenes such as ethylbenzene react with NBS to give products in which bromine substitution has occurred at the benzylic position. Explain the result, and propose a mechanism.

Tom Rutherford

Numerade Educator

Problem 67

Predict the product(s) of the following reaction, indicating stereochemistry:

Nicole Krahulik

Nicole Krahulik

Numerade Educator

Problem 68

Metabolism of S-adenosylhomocysteine (Section $12-11$ ) involves the following steps. Propose mechanisms for both.

Lainey Roebuck

Numerade Educator

Problem 69

Reaction of iodoethane with CN $^{-}$ yields a small amount of isonitrile, $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{~N} \equiv \mathrm{C}$, along with the nitrile $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{C} \equiv \mathrm{N}$ as the major product.
Write electron-dot structures for both products, and propose mechanisms to account for their formation.

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 70

Internal alkynes can be made from terminal alkynes by converting the terminal alkyne to an acetylide anion and then treating the anion with a primary alkyl halide. Propose a mechanism for the alkylation. (See Section $8-15 .)$
$$
\mathrm{RC} \equiv \mathrm{CH} \quad \frac{1 . \mathrm{NaNH}_{2}}{2 \mathrm{R}^{\prime} \mathrm{CH}_{2} \mathrm{Br}} \quad \mathrm{RC} \equiv \mathrm{CCH}_{2} \mathrm{R}^{\prime}
$$

Ian Kaigh

Numerade Educator

Problem 71

Alkynes can be made by dehydrohalogenation of vinylic halides in a reaction that is essentially an E2 process. In studying the stereochemistry of this elimination, it was found that $(Z)-2$ -chlorobut2-enedioic acid reacts 50 times as fast as the corresponding $E$ isomer. What conclusion can you draw about the stereochemistry of eliminations in vinylic halides? How does this result compare with eliminations of alkyl halides?

Lainey Roebuck

Numerade Educator

Problem 72

(S)-Butan-2-ol slowly racemizes on standing in dilute sulfuric acid. Explain.

Shalini Tyagi

Numerade Educator

Problem 73

Reaction of HBr with $(R)-3$ -methylhexan-3-ol leads to racemic 3 -bromo3-methylhexane. Explain.

George Bennett

Numerade Educator

Problem 74

Treatment of 1-bromo-2-deuterio-2-phenylethane with strong base leads to a mixture of deuterated and nondeuterated phenylethylenes in a ratio of approximately $7: 1 .$ Explain.

Lainey Roebuck

Numerade Educator

Problem 75

We saw in Section $8-3$ that an alkene can be converted into a bromo-hydrin on treatment with $\mathrm{Br}_{2}$ in the presence of water. When the bromohydrin is then treated with base, an epoxide is formed. Propose a mechanism for the epoxide formation, using curved arrows to show the electron flow.

Anupa Sharad Medhekar

Anupa Sharad Medhekar

Numerade Educator

Problem 76

Show the stereochemistry of the epoxide (Problem 12.75 ) you would obtain by formation of a bromohydrin from trans-but-2-ene, followed by treatment with base.

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 77

One step in the urea cycle for ridding the body of ammonia is the conversion of argininosuccinate to the amino acid arginine plus fumarate. Propose a mechanism for the reaction, and show the structure of arginine.

Anand Jangid

Numerade Educator

Problem 78

Propose a structure, including stereochemistry, for an alkyl halide that gives only (E)-3-methyl-2-phenylpent-2-ene on E2 elimination.

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 79

When a primary alcohol is treated with $p$ -toluenesulfonyl chloride at room temperature in the presence of an organic base such as pyridine, a tosylate is formed. When the same reaction is carried out at higher temperature, an alkyl chloride is often formed. Explain.

Lainey Roebuck

Numerade Educator

Problem 80

$\mathrm{S}_{\mathrm{N}} 2$ reactions take place with inversion of configuration, and $\mathrm{S}_{\mathrm{N}} 1$ reactions take place with racemization. The following substitution reaction, however, occurs with complete retention of configuration. Propose a mechanism.

Lainey Roebuck

Numerade Educator

Problem 81

Propose a mechanism for the following reaction, an important step in the laboratory synthesis of proteins:

Lainey Roebuck

Numerade Educator

Problem 82

The amino acid methionine is formed by a methylation reaction of homocysteine with $N$ -methyltetrahydrofolate. The stereochemistry of the reaction has been probed by carrying out the transformation using a donor with a "chiral methyl group" that contains protium (H), deuterium (D), and tritium (T) isotopes of hydrogen. Does the methylation reaction occur with inversion or retention of configuration? How might you explain this result?

Lainey Roebuck

Numerade Educator

Problem 83

Amines are converted into alkenes by a two-step process called the Hofmann elimination. Reaction of the amine with excess $\mathrm{CH}_{3}$ I in the first step yields an intermediate that undergoes E2 reaction when treated with basic silver oxide. Pentylamine, for example, yields pent1-ene. Propose a structure for the intermediate, and explain why it undergoes ready elimination.

Travis Maslanik

Travis Maslanik

Numerade Educator

Problem 84

Ethers can often be prepared by $\mathrm{S}_{\mathrm{N}}$ 2 reaction of alkoxide ions, $\mathrm{RO}^{-}$, with alkyl halides. Suppose you wanted to prepare cyclohexyl methyl ether. Which of the two possible routes shown below would you choose?

Anupa Sharad Medhekar

Anupa Sharad Medhekar

Numerade Educator

Problem 85

How might you use a Suzuki-Miyaura coupling to prepare the following biaryl compound? Show the two potential reaction routes.

Tom Rutherford

Numerade Educator