Deck 18: Ethers and Epoxides;thiols and Sulfides

Question 1

Exhibit 18-3
Consider the data below to answer the following question(s).
​
Epoxides are synthesized industrially in one step by silver oxide air oxidation of ethylene and on a laboratory scale in one step by treating an alkene with m-chloroperoxybenzoic acid.An alternative two-step process converts alkenes to halohydrins,which are converted by treatment with base to epoxides.
​
Refer to Exhibit 18-3.The synthesis of epoxides by base treatment of halohydrins is an example of an intramolecular:

A)S_N1 reaction
B)hydrolysis reaction
C)dehydration reaction
D)Williamson ether synthesis

Answer 1

Williamson ether synthesis

Question 2

Draw: 12-crown-4

Answer 2

Question 3

Draw: cyclopropyl ethyl sulfide

Answer 3

Question 4

Diphenyl ether is inert to cleavage by HI or HBr.Explain.

Question 5

Exhibit 18-1
Consider the reaction below to answer the following question(s).
Refer to Exhibit 18-1.Alternatively,cyclopentyl methyl ether may be synthesized from cyclopentene.Outline a synthesis of cyclopentyl methyl ether from cyclopentene.

Question 6

When 1,2-epoxypropane is treated with sodium ethoxide in ethanol 1-ethoxy-2-propanol is the major product while only a trace amount of 2-ethoxy-1-propanol is produced.Explain these results based on the reaction mechanism.

Question 7

Exhibit 18-2
Consider the data below to answer the following question(s).
Acetals are a special class of ethers which have two ether linkages at a single carbon.Tetrahydropyranyl ethers are acetals that are easily cleaved with mild aqueous acids at room temperature to yield alcohols.
Refer to Exhibit 18-2.Draw arrows showing the electron flow for this reaction on the structures provided below.

Question 8

Exhibit 18-1
Consider the reaction below to answer the following question(s).
Refer to Exhibit 18-1.Write the complete stepwise mechanism for the reaction.Show all intermediate structures and all electron flow with arrows.

Question 9

Draw: allyl benzyl ether

Question 10

Draw: 1-isopropoxycyclopentene

Question 11

Exhibit 18-3
Consider the data below to answer the following question(s).
​
Epoxides are synthesized industrially in one step by silver oxide air oxidation of ethylene and on a laboratory scale in one step by treating an alkene with m-chloroperoxybenzoic acid.An alternative two-step process converts alkenes to halohydrins,which are converted by treatment with base to epoxides.
​
Refer to Exhibit 18-3.Show electron flow with arrows on the structures provided below for each step in the above transformation.

Question 12

Name:

Question 13

Name:

Question 14

Exhibit 18-1
Consider the reaction below to answer the following question(s).
Refer to Exhibit 18-1.Mechanistically,the Williamson ether synthesis outlined above is:

A)an E1 process
B)an S_N1 process
C)an E2 process
D)an S_N2 process

Question 15

Exhibit 18-2
Consider the data below to answer the following question(s).
Acetals are a special class of ethers which have two ether linkages at a single carbon.Tetrahydropyranyl ethers are acetals that are easily cleaved with mild aqueous acids at room temperature to yield alcohols.
Refer to Exhibit 18-2.This ether cleavage occurs so easily under such mild conditions because the carbocation intermediate in step two is very stable.Explain why this carbocation is stabilized.

Question 16

Draw: tetrahydrofuran

Question 17

Write the complete stepwise mechanism for the reaction below.Show all electron flow with arrows and draw all intermediate structures.

Question 18

Name:

Question 19

Draw: 3-methyl-1-butanethiol

Question 20

Draw: diethyl ether

Question 21

Propose a synthesis for the following compound using benzene or toluene and any other reagents necessary.Show all major intermediate compounds that would probably be isolated during the course of your synthesis.

Question 22

The following is the proton NMR of a symmetrical alkyl ether.Which peak is most likely due to the protons adjacent to the ether oxygen atom?

A)1
B)2
C)3

Question 23

Choose the best reagent for carrying out the following reactions from the list below.Place the letter of the reagent(s) in the box over the reaction arrow.Use only one letter per box. A.
NaH,then CH₃I
B.
NaOCH₃,CH₃OH
C.
m-ClC₆H₄CO₃H
D.
CH₃MgBr in ether,then H₃O⁺
E.
warm H₂SO₄/H₂O
F.
Hg(O₂CCF₃)₂,CH₃OH
G.
H₂/Pd
H.
PCC,CH₂Cl₂
I.
Cl₂,H₂O
J.
LiAlH₄ in ether,then H₃O⁺

Question 24

Complete the synthetic sequence below by drawing the structures of the reaction in the boxes provided.

Question 25

Name the following compound.Atoms other than carbon and hydrogen are labeled.

Question 26

Name the compound shown below.Atoms other than carbon and hydrogen are labeled.

Question 27

Show how the ether below could be prepared from toluene and any other necessary reagents.Show all reagents and all intermediate structures.

Question 28

Which of the following will undergo rearrangement upon heating?

A)2-butenyl phenyl ether
B)1-propenyl 2-propenyl ether
C)2-pentenyl phenyl ether
D)All will undergo rearrangement.

Question 29

Predict the product of the following reaction.

Question 30

Although not always evident in an IR spectrum,which peak in the IR spectrum below might be due to the C-O stretch of an ether?

A)1
B)2
C)3
D)4

Question 31

Consider the following species.Atoms other than carbon and hydrogen are labeled. Which of the following would be produced upon treatment with I₂?

A)​

B)​

C)​

D)​

Question 32

What is the product formed upon treatment of the following substance with hydrogen peroxide at room temperature,followed by treatment with a peroxyacid? Atoms other than carbon and hydrogen are labeled.

A)
B)
C)
D)

Question 33

Draw the structure of the ether that could be used to produce the following compound.