Note: Missed the last week or so of classes because of business and going to Anchorage.

Now working in Ch 7; pp 226+/-

Alkene hydration

• Add water to an alkene
• C=C+H2O -> COH-CH if you have a catalyst
  • electrophile:
    • H+ (ie acid)
    • HgOAc+
    • BH3-"Hydrobration/oxidation"
    • BH3 & H2O2,OH-,H2O added to cyclic alkene
      • Facts:
        1. Syn
        2. Orientation is non-Markarvikof
           1. Markarvik orientation is OH attaches to the ring where the most H's are (ie CH3)

BH3 Borane

• Leaves an empty P orbital.
• Isoelectronic
• Wants to fill the P orbital
• Tends toward B2H6 sometimes to fill the P orbital, sharing H

When BH3 collides with the C2H4 you wind up with an alkyl borane; then you get 2 more collisions/combinations yielding trialkyl boran

• Add H2O2
  • OH replaces B exactly in place
  • The Borine ends up as boric salt (H3BO3

Why this is a non-Markonikov

1. Electronic

• Transition state has a + charge kiticorner from the boron atom (the boron is electrophylic); the boron atom has a - charge (this is only during the attachment of the borane to the alkene

1. Steric

• Less crowded carbon is the one the boron is most likely to attach to.

3-methyl-1-butene b. hydration

1. add BH3
2. add H2O2

3-methyl-1-butene oxymercury hydration {???}

1. add Hg(Oac)2
2. add NaBH4

3-methyl-1-butene ?? hydration

1. add H3O+

All these result in different products.

SYN steriochemical reactions

Hydrogenation: add H2. This is always a SYN addition.

1. 1,2dimethyl-hexene?+H2+Pt (catalyst such as platinum)
2. The catalyst surface provides a surface onto which the hydrogen atoms bond, thus breaking the H2 bond.
3. The alkene then bonds to the hydrogen and the other C bonds to the surface of the platinum
4. Then another hydrogen attaches to the "alkene", and you now have 1,2dimethyl-hexane

Hydroxylation: add 2 OH

• Read about it in the book

Alkene Cleavage

"Ozonalysis"

• Reaction that breaks the alkene
• Uses ozone to do the cutting
• Take CH3C=CH2 and add:

1. Ozone (O3)
2. Zn,H2O
   • yields C2=O + C=O
   • mechanism is not important