Stereochemistry of Alkene Additions
Explore the stereochemical outcomes of various addition reactions to alkenes, including syn and anti additions, and their implications for product formation.
Includes
Standards
Topics
Stereochemistry of Alkene Additions
Name:
Date:
Score:
Read each question carefully and provide your best answer. Some questions may require drawing structures.
1. Which of the following reactions typically proceeds via a syn addition mechanism?
Halogenation (Br2 addition)
Hydroboration-oxidation
Acid-catalyzed hydration
Oxymercuration-demercuration
2. An anti addition to an alkene results in:
Addition of substituents to the same face of the alkene.
Addition of substituents to opposite faces of the alkene.
Formation of only one enantiomer.
Rearrangement of the carbon skeleton.
3. The addition of HBr to an alkene typically follows 's rule, leading to the more substituted product.
4. When a chiral center is formed in an alkene addition reaction, a of enantiomers is often produced if the starting alkene is achiral.
5. Explain the difference between syn and anti addition in the context of alkene reactions.
6. For the reaction of cis-2-butene with Br2, would you expect a racemic mixture or a meso compound? Justify your answer.
7. Hydroxylation of an alkene using OsO4 followed by NaHSO3/H2O results in an anti addition of two hydroxyl groups.
True
False
8. The formation of a bromonium ion intermediate during halogenation of an alkene is responsible for the anti stereoselectivity.
True
False
9. Draw the complete reaction mechanism, including all intermediates and stereochemical considerations, for the addition of Br2 to trans-2-butene.