Chapter 8: Alkenes


Homework:  1, 3-5, 7-10, 13, 15, 17, 20, 23, 25-27, 30, 33- 35, 40, 41 (not g), 42, 53, and 55.

Hint:  Make flash cards of the reactions.

Lecture Outline 10/31/97
              Reading:  Sections 1-3

Addition Reactions of Alkenes
        
A.  Electrophilic addition - The alkene attacks an electrophile resulting in a carbocation.  Subsequent attack  of a nucleophile on the positive charge gives product.


B.  Addition Reactions
        1.  Addition of H-X
                a.  Markovnikov addition - halide (nucleophile) adds to the most substituted side of the double bond.
                b.  Anti-Markovnikov addition - free radical addition of HX to an alkene.

Lecture Outline 11/3/97
               Reading:  Sections 4-6

        2.  Hydration of alkenes - water adds across an alkene to yield the alcohol (Markovnikov addition).
                a.  Acid catalyzed
                b.  Addition of H₂SO₄ followed by hydrolysis.
                c.  Oxymercuration-demercuration - mercury mediated addition of water (or alcohols).

Lecture Outline 11/5/97
               Reading:  Sections 7-9

        3.  Hydroboration - net addition of water to a double bond, but anti-Markovnikov addition.
        4.  Hydrogenation - reduction of an alkene to the saturated hydrocarbon (addition of H₂).
        5.  Carbene addition - generate cyclopropanes
                a.  Simmons-Smith 
                b.  Dihalocarbenes
 
Lecture Outline 11/7/97
               Reading:  Sections 10-13

       6.  Halogen addition
                a.  Bromonium ion intermediate
                b.  Stereospecific reaction
        7.  Halohydrin formation - Markovnikov addition, stereospecific
        8.  Epoxidation
                a.  Addition of an Oxygen to an alkene
                b.  Ring opening of epoxides by acid catalysis.

Exam 3, 11/12/97, will cover material to this point.

Lecture Outline 11/10/97
              Reading:  Sections 14-15

        9.  Dihydroxylation - form an alcohol on each side of the alkene
                a.  Osmium Tetroxide - OsO₄ and peroxide
                b.  Permanganate - KMnO₄ and base (NaOH)
        10.  Oxidative cleavage - division of the alkene into carbonyl groups 
                a.  Permanganate - warm KMnO₄, forms ketones if C of alkene is disubstituted and carboxylic  acids if C of alkene is monosubstituted.
                b.  Ozonolysis - O₃, forms ketones if if C of alkene is disubstituted and aldehydes if C of alkene is monosubstituted.