addition reactions

hydration

alkene reacts with water to form alcohol

hydration forms

Markovnikov

oxymercuration-demercuration steps

1. form mercurinium

2. water opens ring

3. demercuration replaces mercuric with alcohol via NaBH4

alkyloxymercuration-demercuration

alcohol nucleophilic attack to mercurinium 

hydroboration-oxidation

alkene → anti-Markovnikov alcohol

hydroboration oxidation mechanism

peroxide effect

BH3 is e- deficient & adds itself to less substituted end to form radical

syn addition

halogen addition steps

1. form halonium

2. 2nd halide ion attacks backside

halogen addition is

anti addition

formation of halohydrin

alcohol & halogen on adjacent carbons

steps of halohydrin formation

1. halonium

2. H2O backside attack

formation of a halohydrin is

anti-addition

markovnikov product 

catalytic hydrogenation of alkenes

syn addition of H2 to alkene

carbene addition

form cyclopropane with alkene

simmons-smith addition

methylene iodide & to Zn(Cu)

epoxidation of alkene

alkene + peroxyacid to form 3 member cylic ether epoxide

acid catalyzed opening of epoxides

slightly acidic solvent protonates epoxide to form glycol

acid catalyzed opening of epoxide steps

1. protonation of epoxide

2. H2O nucleophilic backside attack

3. deprotonation

syn dihydroxylation

add OH to same face of C=C via OsO4 OR KMnO4