12. Alcohols, Ethers, Epoxides and Thiols

Draw the mechanism if it involves general-acid catalysis.

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

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

(c)

Show how each of the following compounds can be synthesized from an alkene:

a.

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.

b. Which step is the rate-determining step?

a. Draw the product or products that will be obtained from the reaction of cis-2-butene and trans-2-butene with each of the following reagents. If a product can exist as stereoisomers, show which stereoisomers are formed.

8. CH₃OH + H₂SO₄

b. With which reagents do the two alkenes react to form different products?

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

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

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

b.

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

g.

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

d.

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

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

3.

4.