10. Addition Reactions

What stereoisomers are obtained from each of the following reactions?

b.

The acid-catalyzed dehydration we learned in this chapter is reversible, as shown below.

(b) Without looking back, how do you know this mechanism is correct?

Predict the products of the following hydration reactions.

a. 1−methylcyclopentene + dilute acid

A chemist unsuccessfully attempted to produce the 1,4-cyclohexanediol by hydration of the cyclohexene shown.

(a) Provide a mechanism for the formation of the actual product.

(b) Suggest a pathway using acetyl chloride as a protecting group that will allow for the formation of the desired product.

In Chapter 8, we learned about the chemistry of terpenes and the interesting reactions they can undergo. One such reaction is the acid-catalyzed conversion of nerol to terpineol. Suggest a mechanism for this transformation

.

What is the major product of the reaction of 2-methyl-2-butene with each of the following reagents?

g. H₂O + H₂SO₄

Propose a mechanism to show how 3,3-dimethylbut-1-ene reacts with dilute aqueous H₂SO₄ to give 2,3-dimethylbutan-2-ol and a small amount of 2,3-dimethylbut-2-ene.

HINT: When predicting products for electrophilic additions, first draw the structure of the carbocation (or other intermediate) that results from electrophilic attack.

Predict the product(s) that would result when the following molecules are allowed to react under the following conditions: (iii) H₂SO₄ , H₂O . If there is no reaction, write 'no reaction.'

(a)

The acid-catalyzed dehydration we learned in this chapter is reversible, as shown below.

(c) Which side of the reaction would be favored by running the reaction at low temperatures?

Suggest a reagent to carry out each of the following conversions to an alcohol.

(b)

Devise a synthesis for each compound, starting with methylenecyclohexane and any other reagents you need.

a. 1-methylcyclohexanol

The acid-catalyzed dehydration we learned in this chapter is reversible, as shown below.

(a) Propose a mechanism for the formation of an alcohol from an alkene.

The acid-catalyzed dehydration we learned in this chapter is reversible, as shown below.

(d) How might you shift the equilibrium to the right?

Provide the expected product for the reaction of each of the following alkenes with H₂SO₄ and H₂O.

(d)

Propose mechanisms consistent with the following reactions.

(b)