10. Addition Reactions

Ethylene oxide reacts readily with HO^- because of the strain in the three-membered ring. Explain why cyclopropane, a compound with approximately the same amount of strain, does not react with HO^-.

Propose a mechanism for each of the following reactions:

a.

Three arene oxides can be obtained from phenanthrene.

d. Which of the three phenanthrene oxides is most likely to be carcinogenic?

How do the major products obtained from rearrangement of the following arene oxides differ?

What products are obtained from the reaction of cyclohexene oxide with

a. methoxide ion?

Draw all possible resonance contributors for the two carbocations in the preceding reaction. Use the resonance contributors to explain why 1-naphthol is the major product of the reaction.

The existence of the NIH shift was established by determining the major product obtained from rearrangement of the following arene oxide, in which a hydrogen has been replaced by a deuterium.

b. What would be the major product if the carbocation forms phenol by losing H⁺ or D⁺, rather than by going through the NIH shift?

Which of the following reactions occurs more rapidly?

What products are obtained from the reaction of cyclohexene oxide with

b. methylamine?

b. A small amount of a product containing a six-membered ring is also formed. Draw the structure of that product.

c. Why is so little six-membered ring product formed?

What stereoisomers are obtained from the reaction of the alkenes in [PROBLEM 10-32] with a peroxyacid ­followed by reaction with hydroxide ion?

a. trans-2-butene

b. cis-2-butene

What stereoisomers are obtained from the reaction of the alkenes in [PROBLEM 10-32] with a peroxyacid ­followed by reaction with hydroxide ion?

c. cis-2-pentene

d. trans-2-pentene

Three arene oxides can be obtained from phenanthrene.

c. If a phenanthrene oxide can lead to the formation of more than one phenol, which phenol will be obtained in greater yield?

Cellosolve® is the trade name for 2-ethoxyethanol, a common industrial solvent. This compound is produced in chemical plants that use ethylene as their only organic feedstock. Show how you would accomplish this industrial process.

Show the rest of the mechanism for formation of the cyclized intermediate in Figure 14-6.