10. Addition Reactions

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by determining the major product obtained from rearrangement of the following arene oxide, in which a hydrogen has been replaced by a deuterium.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.

Predict the products of the following reactions.

(g) trans-2,3-epoxyoctane + H⁺, H₂O

(h) propylene oxide + methylamine (CH₃NH₂)

Propylene oxide is a chiral molecule. Hydrolysis of propylene oxide gives propylene glycol, another chiral molecule.

(a) Draw the enantiomers of propylene oxide.

(b) Propose a mechanism for the acid-catalyzed hydrolysis of pure (R)-propylene oxide.

Predict the major products of the following reactions, including stereochemistry.

f. trans-pent-2-ene + peroxyacetic acid in water

a. Propose a mechanism for the conversion of cis-hex-3-ene to the epoxide (3,4-­epoxyhexane) and the ring-opening reaction to give the glycol, hexane-3,4-diol. In your mechanism, pay particular attention to the stereochemistry of the intermediates and products.

b. Repeat part (a) for trans-hex-3-ene. Compare the products obtained from cis- and trans-hex-3-ene. Is this reaction sequence stereospecific?

Predict the major product when each reagent reacts with ethylene oxide.

(d) PhNH₂ (aniline)

(e) KCN (potassium cyanide)

(f) NaN₃ (sodium azide)