12. Alcohols, Ethers, Epoxides and Thiols

Identify the alkene and alcohol partners that could be used to make the following ethers.

(a)

Predict the product of the following reactions. [Two of them are Williamson ether syntheses. Why isn't the other?].

(c)

Suggest a phenoxide and an alkyl halide to make the following aryl alkyl ethers.

(b)

Two different Williamson ether syntheses can be used to make the compound in (a). Show them. The compound in (b), however, can only be made one way. Show it and explain why a second Williamson ether synthesis is not possible.

(a)

In contrast to Assessment 13.102, only one combination of haloalkane and alkoxide can be used in the Williamson ether synthesis to make the ether shown. Identify the combination and explain why it is the only combination that works.

Predict the product of the following reactions. [Two of them are Williamson ether syntheses. Why isn't the other?].

(b)

In Chapter 12, we learned that crown ethers were used to increase the rate of S_N2 reactions (Assessment 12.80). Suggest a synthesis of 15-crown-5 using the reactions learned here in Chapter 13.

Suggest a phenoxide and an alkyl halide to make the following aryl alkyl ethers.

(a)

Provide the reagents necessary to carry out the following synthesis. What is the purpose of steps (a) and (e)?

How could you synthesize isopropyl propyl ether, using isopropyl alcohol as the only carbon-containing reagent?

Draw the product of each of the following reactions:

2.

What is the best way to prepare the following ethers using an alkyl halide and an alkoxide ion?

c.

d.

A chemist wanted to synthesize the anesthetic 2-ethoxy-2-methylpropane. He used ethoxide ion and 2-chloro-2-methylpropane for his synthesis and ended up with no ether. What was the product of his synthesis? What reagents should he have used?

Design a synthesis for each of the following, using an intramolecular reaction:

e.

The compound shown below has three different types of OH groups, all with different acidities. Show the structure produced after this compound is treated with different amounts of NaH followed by a methylating reagent. Add a brief explanation.

(a) 1 equivalent of NaH, followed by 1 equivalent of CH₃I and heat

(b) 2 equivalents of NaH, followed by 2 equivalents of CH₃I and heat

(c) 3 equivalents of NaH, followed by 3 equivalents of CH₃I and heat