Ethers and Epoxides; Thiols and Sulfides

Name the following ethers:

a) 

Name the following ethers:

b) 

Name the following ethers:

c) 

Name the following ethers:

d) 

Name the following ethers:

e) 

Name the following ethers:

f) 

How would you prepare the following ethers using a Williamson synthesis?

1. Methyl propyl ether
2. Anisole (methyl phenyl ether)
3. Benzyl isopropyl ether
4. Ethyl 2,2-dimethylpropyl ether

How would you prepare the following ethers using a Williamson synthesis?

1. Methyl propyl ether
2. Anisole (methyl phenyl ether)
3. Benzyl isopropyl ether
4. Ethyl 2,2-dimethylpropyl ether

How would you prepare the following ethers using a Williamson synthesis?

1. Methyl propyl ether
2. Anisole (methyl phenyl ether)
3. Benzyl isopropyl ether
4. Ethyl 2,2-dimethylpropyl ether

Why do you suppose only symmetrical ethers are prepared by the sulfuric acid-catalyzed dehydration procedure? What product (s) would you expect if ethanol and 1-propanol were allowed to react together? In what ratio would the products be formed if the two alcohols were of equal reactivity?

How would you prepare the following ethers using a Williamson synthesis?

1. Methyl propyl ether
2. Anisole (methyl phenyl ether)
3. Benzyl isopropyl ether
4. Ethyl 2,2-dimethylpropyl ether

Review the mechanism of oxymercuration shown in Figure 8-3 on page 230, and then write the mechanism of the alkoxymercuration reaction of 1-methyl-cyclopentene with ethanol. Use curved arrows to show the electron flow in each step.

Rank the following halides in order of their reactivity in Williamson synthesis:

1. Bromoethane, 2-bromopropane, bromobenzene
2. Chloroethane, bromoethane, 1-iodopropene

Rank the following halides in order of their reactivity in Williamson synthesis:

1. Bromoethane, 2-bromopropane, bromobenzene
2. Chloroethane, bromoethane, 1-iodopropene

How would you prepare the following ethers? Use whichever method you think is more appropriate, Williamson synthesis or the alkoxymercuration reaction.

1. Butyl cyclohexyl ether
2. Benzyl ethyl ether ( ${\mathbf{C}}_6{\mathbf{H}}_5{\mathbf{CH}}_2{\mathbf{OCH}}_2{\mathbf{CH}}_3$)
3. sec-Butyl tert-butyl ether
4. Tetrahydrofuran

Predict the products of the following reactions:

a) 

Predict the products of the following reactions:

Write the mechanism of the acid-induced cleavage of tert-butyl cyclohexyl ether to yield cyclohexanol and 2-methylpropene.

Why are HI and HBr more effective than HCl in cleaving ethers? (See Section 11-3).

What product would you expect from Claisen rearrangement of 2-butenyl phenyl ether?

Reaction of cis-2-butene with m-chloroperoxybenzoic acid yields an epoxide different from that obtained by reaction of the trans isomer. Explain.

Predict the major product of each of the following reactions:

How would you prepare the following diols?

Predict the major product of the following reactions:

15-Crown-5 and 12-crown-4 ethers complex Na⁺ and Li⁺, respectively. Make models of these crown ethers, and compare the sizes of the cavities.

Name the following compounds:

2-Butene-1-thiol is one component of skunk spray. How would you synthesize this substance from methyl 2-butenoate? From 1,3-butadiene?

The ¹H NMR spectrum shown is that of a cyclic ether with the formula C₄H₈O. Propose a structure.

The Zeisel method is an old analytical procedure for determining the number of methoxyl groups in a compound. A weighed amount of the compound is heated with concentrated HI, ether cleavage occurs, and the iodomethane product is distilled off and passed into an alcohol solution of ${\mathbf{AgNO}}_3$ , where it reacts to form a precipitate of silver iodide. The AgI is then collected and weighed, and the percentage of methoxyl groups in the sample is thereby determined. For example, 1.06 g of vanillin, the material responsible for the characteristic odour of vanilla, yields 1.60 g of AgI. If vanillin has a molecular weight of 152, how many methoxyl groups does it contain?

Disparlure, ${\mathbf{C}}_{19}{\mathbf{H}}_{38}\mathbf{O}$, is a sex attractant released by the female gypsy   moth, Lymantria dispar. The  ${}^1\mathrm{H}$ NMR spectrum of disparlure shows a   large absorption in the alkane region, 1 to 2 d, and a triplet at 2.8 d. Treatment of disparlure, first with aqueous acid and then with ${\mathbf{KMnO}}_4$,  yields two carboxylic acids identified as undecanoic acid and 6-methyl- heptanoic acid. ( ${\mathbf{KMnO}}_4$,cleaves 1, 2-diols to yield carboxylic acids).  Neglecting stereochemistry, propose a structure for disparlure. The actual compound is a chiral molecule with 7R, 8S stereochemistry.   Draw disparlure, showing the correct stereochemistry.

How would you synthesize racemic disparlure (Problem 18-63) from   compounds having ten or fewer carbons?

How could you prepare benzyl phenyl ether from benzene and phenol? More than one step is required.

How would you synthesize anethole (Problem 18-54) from phenol?

Give IUPAC names for the following compounds (reddish brown 5 Br; yellow 5 S):

Show the product, including stereochemistry, that would result from reaction of the following epoxide with HBr

Show the product, including stereochemistry, that would result from reaction of the following epoxide with HBr

Show the product, including stereochemistry, of the following reaction:

Treatment of the following alkene with a peroxy acid yields an epoxide different from that obtained by reaction with aqueous Br₂ followed by base treatment. Propose structures for the two epoxides, and explain the result.

Predict the product(s) and provide the mechanism for each reaction below. What does each mechanism have in common?

Predict the product(s) and provide the mechanism for each reaction below. What does each mechanism have in common?

Predict the product(s) and provide the mechanism for each two-step process below.

Predict the product(s) and provide the mechanism for each two-step

process below.

The alkoxymercuration of alkenes involves the formation of an organomercury intermediate (I), which is reduced with NaBH4 to give an etherproduct. For each reaction below, predict the ether product and provide the mechanism formation.

(a) 

(b)

(c)

The alkoxymercuration of alkenes involves the formation of an organomercury intermediate (I), which is reduced with NaBH4 to give an ether product. For each reaction below, predict the ether product and provide the mechanism formation.

a.

b.

c.

Predict the product(s) and provide the mechanism for each reaction below. What do the mechanisms have in common?

a.

b.

c.

d.

Predict the product(s) and provide the mechanism for each reaction below. What do the mechanisms have in common?

a. 

b. 

c.

d.

Predict the product(s) and provide the mechanism for each reaction below. What do the mechanisms have in common?

a.

b.

c.

d.

Predict the product(s) and provide the mechanism for each reaction below. What do the mechanisms have in common?

a. 

b.

c.

d.

In the formation of the prepolymer used to make epoxy resins, a bisphenol reacts with epichlorohydrin in the presence of a base. Show the product and mechanism when two moles of phenol react with epichlorohydrin.

In the formation of the prepolymer used to make epoxy resins, a bisphenol reacts with epichlorohydrin in the presence of a base. Show the product and mechanism when two moles of phenol react with epichlorohydrin.