Predict the product of the following reactions.
(d)

Using cyclooctyne as your starting material, show how you would synthesize the following compounds. (Once you have shown how to synthesize a compound, you may use it as the starting material in any later parts of this problem.)

(a) cis-cyclooctene

(b) cyclooctane

(c) trans-1,2-dibromocyclooctane

a. What is the major product obtained from the reaction of propene and Br₂ plus excess Cl^-?

b. Indicate the relative amounts of the stereoisomers that are obtained.

When Br₂ adds to a cis alkene that has different substituents attached to each of the two sp² carbons, such as cis-2-heptene, identical amounts of the two threo enantiomers are obtained even though Br^- is more likely to add to the less sterically hindered carbon of the bromonium ion. Explain why identical amounts of the two enantiomers are obtained.

Propose a mechanism for the following reactions:

b.

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

h.

Which stereoisomer of 3-hexene forms a meso compound when it reacts with Br₂?

Draw the products of the following reactions. If the products can exist as stereoisomers, show which stereoisomers are formed.

c.