AlkenesAddition ReactionsSynthesis
Addition of HBr or HClMarkovnikov Addition
HBr Addition with RO-ORAnti-Markovnikov
Free-Radical Mechanism
Addition of Br2
A Similar Mechanism to the Addition of HBr?
Trans is formed exclusively(No cis is formed)
Carbocation can be Stabilized by Neighboring Br
Bromonium Ion is Opened Equally from Both Sides
DefinitionsStereospecific only one stereoisomer is formed at the expense of the other (e.g. trans vs. cis)Stereoselective one stereoisomer is formed preferentially over the other.
Anti-Addition Stereospecific ReactionAnti-addition
Bromonium Ion Intermediate
Halohydrins
Bromohydrin FormationAddition of Br OHStereospecific & Regiospecific
Unsymmetrical Bromonium ionH2O opens ring at more hindered site
Br and OH are trans in anti addition
Catalytic Hydrogenationsyn addition
Mechanism Syn Addition
Syn Addition of H2
Hydrogenationall alkene p bonds are reduced
Hydrogenated Vegetable Oil
HydrationAddition of H2O
Oxymercuration HydrationMarkovnikov additionRegiospecific Reaction
Oxymercuration Mechanism
Predict the Oxymercuration Hydration Products
What Alkene would you use to Make These Alcohols?
Hydroboration Hydration Anti-Markovnikov Syn addition
BH3 adds to Alkene
Hydroboration
Regiochemistry is Anti-Markovnikov
Syn Addition of H2O
Draw the Major Products
2 Complementary Hydration Reactions
Oxymercuration the more highly substituted alcohol formsHydroboration the less highly substituted alcohol forms
Predict Both Oxymercuration and Hydroboration Products
Cyclopropanation
A Carbene is Similar to Geometry of a Carbocation
Dichlorocarbene Reactions
Simmons-Smith Reaction
In situ Preparation of Carbene
Two MCAD Inhibitors
Epoxide PreparationFrom Alkenes
Epoxide PreparationFrom Halohydrins
Mechanism
Epoxide groups are Common in Biologically Active Molecules
A New Class of Anti-tumor Agents
Ozonolysis Forms 2 Carbonyl Compounds
OzonolysisAlkene Cleavage
Mechanism of Ozonolysis
What Alkene will Undergo Ozonolysis to Give the Products Shown?
Addition polymers
Air Pollution Reacts with Tires
O3 reacts with all alkene p Bonds
Problem A symmetrical unknown compound A, C8H16, reacts with H2 on a 1% Pt/C catalyst to form B (C8H18). Treatment of A with O3 followed by Zn/HOAc affords butanone only. Identify A and B.