OChem Test 4

UGUGHHHHHHHHHHHHHHHH

+ HX (X = Cl, Br, I)

Hydrohalogenation

Follows Markovnikov Addition

+ HBr, ROOR (peroxide)

Anti-Markovnikov Addition

Follows anti-Markovnikov addition (duh)

Is prone to rearrangement

If a chiral center is formed, we get a racemic mixture

+ H₃O⁺

Acid-Catalyzed Hydration

Follows Markovnikov addition

If a chiral center is formed, we get a racemic mixture

This reactants and products are in equilibrium here and can be controlled

+ 1.) Hg(OAc)₂, H₂O

2.) NaBH₄

Oxymercuration-Demurcuration

Follows Markovnikov addition

NO REARRANGEMENTS

Forms a mercurinium ion intermediate (triangle-looking bond)

+ 1.) BH₃ THF

2.) H₂O₂, NaOH

Hydroboration-Oxidation

Adds H and OH with anti-Markovnikov addition in a SYN fashion

If a chiral center is formed, a pair of enantiomers is formed by addition to either face of the alkene

+ H₂, Pt

Catalytic Hydrogenation

The addition of H₂ across an alkene

Only SYN addition is observed

+ Br₂

Halogenation

The addition of two halogen atoms across an alkene

Only ANTI addition is observed

Forms a bromonium ion intermediate (triangle bond)

This is stereospecific, and the starting alkene determines the stereochem of the products

+ Br₂, H₂O

Halohydrin Formation

Formed when halogenation is conducted in water, water acts as nucleophile that attacks the bromonium ion

The halide adds to the LESS SUBSTITUTED CARBON

The OH adds to the MORE SUBSTITUTED CARBON

+ 1.) RCO₃H

2.) H₃O⁺

Anti Dihydroxylation

A two step procedure where the peroxyacid (RCO₃H) is the reagent and forms an epoxide (triangle bond), resulting in an ANTI product

+ KMnO₄, cold NaOH

OR

+ 1.) OsO₄

2.) NaHSO₃, H₂O

Syn Dihydroxylation

Adds OH and OH across the alkene in a concerted, SYN fashion

+ 1.) O₃

2.) DMS

Ozonolysis/Oxidative Cleavage

A one step process where alkenes are ‘cut’ in half