Alkene Addition Reactions

Final Organic Chemistry 1 Exam

name all of the reactions (5 types, #3 has a-c)

1) hydrogenation

2) hydrohalogenation

3) hydration

a. acid-catalyzed

b. oxymercuration-demurcuration

c. hydroboration-oxidation

4) halogenation

5) halohydrin formation

give an overview of hydrogenation (what does it involve, regioselectivity, stereochemistry, type of process, exothermic or endothermic, rearrangements)

- H2/metal catalyst (Pd, Pt, Ni)

- regioselectivity: none

- stereochemistry: syn addition

- process: concerted

- ALWAYS exothermic

- rearrangements: no

give an overview of hydrohalogenation (what does it involve, regioselectivity, stereochemistry, rearrangements)

- HX (X=Cl, Br, I), or HBr/ROOR (peroxide)

- regioselectivity: markovnikov, but exception is anti-markovnikov

- stereochemistry: no

- rearrangements: possible

give an overview of all 3 hydration reactions (what they involve, regioselectivity, stereochemistry, rearrangements)

a. acid-catalyzed hydration

- H2SO4/H2O (treated as “H3O+”)

- regioselectivity: markovnikov

- stereochemistry: no

- rearrangements: possible

b. oxymercuration-demurcuration

- 1. Hg(OAc)2, H2O; 2. NaBH4 (treated as “HgOAc+” and “OAc-”)

- regioselectivity: markovnikov

- stereochemistry: anti addition (backside attack)

- rearrangements: no

c. hydroboration oxidation

- 1. BH3 * THF (or B2H6); 2. H2O2, NaOH

- regioselectivity: anti-markovnikov

- stereochemistry: syn addition

- rearrangements: no

give an overview of halogenation (what does it involve, regioselectivity, stereochemistry, rearrangements)

- X2 (X=Cl, Br, I)/inert solvent (ex. CH2Cl2)

- regioselectivity: none

- stereochemistry: anti addition (backside attack)

- rearrangements: no

give an overview of halohydrin formation (what does it involve, regioselectivity, stereochemistry, rearrangements)

- X2 (X=Cl, Br, I)/H2O or ROH

- regioselectivity: markovnikov

- stereochemistry: anti addition (backside attack)

- rearrangements: no