Alkene Addition Reactions (CHM 221)

Hydrohalogenation adds

H and X

Hydrohalogenation characteristics

Markovnikov addition

Carbocation intermediate

Rearrangement possible

Hydrohalogenation reagents

HBr, HCl, HI

sometimes ROOR (only with HBr)

Hydrohalogenation with ROOR characteristics

Anti-Markovnikov

No carbocation intermediate

Hydrohalogenation using ROOR can only be used with

HBr

Acid-Catalyzed Hydration adds

H and OH

Acid-Catalyzed Hydration characteristics

Markovnikov addition

Carbocation intermediate

Rearrangement possible

Acid-Catalyzed Hydration reagents

[H2SO4] with H2O

(think H3O+)

Oxymercuration-Demercuration adds

H and OH*

*could form an ether

Oxymercuration-Demercuration characteristics

Markovnikov addition

No carbocation intermediate

No rearrangement

Oxymercuration-Demercuration reagents

1. Hg(OAc)2, H2O*

2. NaBH4, NaOH, H2O

*could be an alcohol

For Oxymercuration-Demercuration, the ______________ is critical

nucleophile

Hydroboration-Oxidation adds

H and OH

Hydroboration-Oxidation characteristics

Anti-Markovnikov addition

No carbocation formed

No rearrangement

Syn addition

Hydroboration-Oxidation reagents

1. BH3 (or BH3 THF or B2H6)

2. H2O2, NaOH, H2O

Hydrogenation adds

H and H

Hydrogenation characteristics

Syn addition

No rearrangement

Hydrogenation reagents

H2 (g)

Pd/Pt/Wilkinson's catalyst

Halogenation adds

X and X

Halogenation characteristics

Anti addition

No carbocation

No rearrangement

Halogenation reagents

Cl2/Br2

CCl4/CH2Cl2/CHCl3

Halohydrins add

X and OH

Halohydrins characteristics

Anti addition

No rearrangement

OH goes to more subbed

X goes to less subbed

Halohydrins reagents

Br2/Cl2 with H2O or ROH

Syn Dihydroxylation adds

2 OH groups

Syn Dihydroxylation Reagents

OsO4 with aqueous Na2SO3/NaHSO3 or cold KMnO4 with aqueous NaOH

Anti Dihydroxylation adds

2 OH groups

Anti Dihydroxylation Reagents

1. Peroxy Acid (mCPBA) (forms epoxide intermediate) 2. H3O+ or H2O w Acid (forms the final product)

Oxidative Cleavage Reagents

O3 with DMS

Oxidative Cleavage

cuts the double bond in half, adds an O on the end of the new double bonds. Also forms DMSO