10. Addition Reactions

Predict the major products of the following reactions, and give the structures of any intermediates. Include stereochemistry where appropriate.

(q)

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

a.

What reagents are needed to carry out the following syntheses?

Show how you would accomplish the following synthetic conversions.

a. 3-methylpent-2-ene → 2-chloro-3-methylpentan-3-ol

Problem-Solving Hint: The opening of a halonium ion is driven by its electrophilic nature. The weak nucleophile attacks the carbon bearing more positive charge.

Predict the product of the following reactions.

(a)

Propose a mechanism for the addition of bromine water to cyclopentene, being careful to show why the trans product results and how both enantiomers are formed.

Predict the major product(s) for each reaction. Include stereochemistry where appropriate.

c. cis-but-2-ene + Cl₂/H₂O

d. trans-but-2-ene + Cl₂/H₂O

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

b.

Suggest an alkene that could be used to make each of the following halohydrins.

(a)

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.

5. Br₂ + H₂O

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

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

e.

Each of the following reactions has two nucleophiles that could add to the intermediate formed by the reaction of the alkene with an electrophile. What is the major product of each reaction?

a.

Predict the product(s) that would result when the alkenes are allowed to react under the following conditions: (iv) Cl₂, CH₃OH

(k)