12. Alcohols, Ethers, Epoxides and Thiols

How could the following compounds be prepared using an alkene as one of the starting materials?

d.

b. Which step is the rate-determining step?

a. Propose a mechanism for the following reaction (show all curved arrows):

What is the major product of each of the following reactions?

g.

How could the following compound be prepared using an alkene as one of the starting materials?

Propose a mechanism for the following reaction (remember to use curved arrows to show the movement of electrons from the nucleophile to the electrophile):

c. What is the electrophile in the first step?

d. What is the nucleophile in the first step?

e. What is the electrophile in the second step?

f. What is the nucleophile in the second step?

Ethers can be synthesized by substituting ethanol for water in the acid-catalyzed hydration reaction. Suggest an arrow-pushing mechanism which accounts for the formation of the ethyl ether under these conditions.

Show how you would accomplish the following transformations. Some of these examples require more than one step.

(a) 2-methylpropene → 2,2-dimethyloxirane

(b) 1-phenylethanol → 2-phenyloxirane

(c) 5-chloropent-1-ene → tetrahydropyran

Draw the mechanism for the following reaction if it involves specific-acid catalysis.

Draw the mechanism if it involves general-acid catalysis.

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

(c)

Draw a reaction coordinate diagram for the acid-catalyzed addition of an alcohol to an alkene. Which step is rate-determining?

What is the major product of each of the following reactions?

3.

4.