Ch. 8 Alkene Reactions

Hydrogenation - Catalytic Reduction

H2 / Pt —- Syn Addition

Hydrohalogenation

H-x / CCl4 —- Markovnikov, Hydrogen Shift, carbocation — X = Cl, Br, I

H-Br / ROOR —— ROOR = peroxides, Anti-markovnikov

Halogenation

X2 / CCl4 —- Anti-addition —- X = Cl, Br

Halohydrin Formation 

X2 / H2O —- Anti, OH = markovnikov, no carbocation, X = Cl, Br

X2 / ROH —→ Forms an ether

Acid Catalyzed Hydration

H2SO4 / H2O —- Markovnikov, H-shift, carbocation

If ROH is used, forms an ether

Oxymercuration - Reduction

Hg(OAc)2 H2O / NaBH4 —- Markovnikov, no H-shift, anti

Alkoxymercuration - Reduction

Hg(OAc)2, ROH / NaBH4 —- Markovnikov, no H-shift, anti

Hydroboration - Oxidation

BH3, THF / NaOH, h2o2 —- Anti-mark, syn

Epoxidation

Peracid —- syn (mCPBA is often used)

Dihydroxylation 

OsO4 —-→ Syn 

or KMnO4  —→ Syn

or mCPBA / H3O+ —→ Anti

Oxidative cleavage

KMnO4 —> 

Ozonlysis

O3 / (CH3)2S —→ primary carbon aldehyde

O3 / h2o2 —→ primary carbon carboxylic acid

Cyclopropanation

CH2I2 / Zn(Cu) —→ Simmons-Smith Rxn

CH3X3 / NaOH / H2O —→ Simmons-Smith Rxn (with bonds from top of ring)

Syn 

Meaning Syn Addition —> Both substituents are added to the same side of a double bond. BOTH WEDGE OR BOTH DASHES IN TERMS OF STEREOCHEMISTRY.

Mark

Meaning Markovnikov —> Something like Br will be added to the more substituted carbon (because it is more stable). The H atom will be added to a lower substituted carbon (like a primary carbon 1)

Anti

Meaning anti-addition. The added substituents are NOT on the same side. ONE IS DASHED AND ONE IS WEDGED. can be interchangeable**8

Anti-markovnikov

A substituent like Br will attach to a less substituted carbon. Like a primary carbon.