reactions of alkenes

hydrogenation

—> with H₂ with metal catalyst (Pd/C or Pt/C) syn addition

Hydration

Oxymercuration-Reduction

1)Hg(OAc)₂/THF/H₂O

2)NaBH₄

or H₃O⁺/H₂O

alcohol addition

alkoxymercuration-reduction

1) Hg(OAc)₂ in alcohol solvent

2) NaBH4 to make OR on more substituted carbon, no carbocation rearrangement, anti addition

acid catalyzed add. of an alcohol

hydrohalogenation

electrophilic addition of HCl/HBr,

• markovnikov’s rulehalogen goes on more substituted carbon

  1. alkene protonated + C=C broken

  2. Halide ion attacks Markovnikov carbon

carbocation rearrangement possible if more stable c-c can be formed through alkyl/halide shift

it will follow Markovnikov's rule except in certain cases like HgOAc

if there is a carbocation intermediate

anti markovnikov

if you do a hydrohalogenation in extreme light or heat the product will be

halogenation in inert solvents

anti addition of halogens

( like CHCl2 or CCl4 )

halohydrin reaction

addition of molecular Br/Cl in water

—>X²/H₂O

• addition of halogen on least sub. carbon,

• addition of hydroxy group on more sub. carbon;

• anti+Markovnikov

—>same mechanism with alcohol solvent

acid catalyzed hydration

—>H₃O⁺/H₂O

adding OH Markovnikov, hydride shift can occur

oxymercuration

1) Hg(OAc)₂ in water solvent,

2) NaBH4 to make OH on more substituted carbon.

No carbocation rearrangement, anti addition, markovnikov

hydroboration oxidation

anti Markovnikov regiochem, syn stereochem addition of an alcohol,

1) BH₃, THF (syn addition of BH₃)

2) H₂O₂, NaOH, H₂O

epoxidation

• peracids like RCO3H and mCPBA

that adds an O attached to both carbons, stereochemistry is preserved

how would you make a product with two OH groups on different sides?

epoxidation and acid catalyzed hydration

how do you make a product with two OH groups on the same side?

1) OsO4 2) KMnO4 or Na2SO3/H2O

ozonolysis with reduction

cleaves pi bond to make two oxygen double bonds; makes ketone; O3 with solvent that does (CH3)2S

ozonolysis with oxidation

cleaves pi bond to make 2 oxygen double bonds; makes carboxylic acid, O3 with solvent that does contain oxygen (H2O2)

cyclopropanation

1) CH2I2/Zn(Cu) or CH2N2, which would create a carbon propane ring

cyclopropanation with chlorine

make carbon propane ring with halogens attached. if you see 3 halogen -> add 2. syn addition

full reduction of an alkyne

H2/metal catalyst will add H completely 2x

how to make a cis alkene from an alkyne?

H2/Lindlar's catalyst

how to make a trans alkene from an alkyne?

Na/NH3

hydration of an alkyne

1) HgSO4, 2)H2S04, H2O; gives us an enol where alcohol Markovnikov, which tautomerizes into a ketone

hydroboration oxidation of an alkyne

1) R2BH, THF 2) H2O2, NaOH, H2O; alcohol anti-Markovnikov, tautomerizes into an aldehyde

hydrohalogenation of an alkyne

X halogen adds to more sub carbon and same carbon if in excess addition

halogenation of an alkyne

X2, 4 halogens added

ozonolysis with terminal alkyne

add double bonded O groups and OH, becomes a carboxylic acid

ozonolysis with internal alkyne

H end will decompose into CO2

permanganate oxidation neutral with alkyne

1) KMnO4/H2O neutral results in 2 OH groups on each carbon, which tautomerizes into double bond C-Os. 2 C-Os made

permanganate oxidation with hot and basicity with alkyne

1) KMnO4/H2O makes O group and oxygen nucleophile

NaNH2/NH3

makes acetalide ion, which is a very good carbon nucleophile

epoxide formation and basic alcoholysis

1) RCO3H, 2) ROH/NAOR; OH on more substituted while OR on less

epoxide formation and acidic alcoholysis

1) RCO3H, 2) ROH/H+; OR to more sub carbon and OH to less sub carbon

mark rule

regioselectivity of addition to unsymmetrical alkenes

• carbocation intermediate

• favors more stable carbocation on MORE substituted carbon

ex: acid catalyzed hydration + hydrohalogenation of alkenes= alkyl halides and alcohols

anti mark rule

regioselectivity of addition to unsymmetrical alkenes

• hydrogen atom adds to the less substituted carbon of an unsymmetrical alkene

• other part of the reagent adds to the more substituted carbon

ex: free radical halogenation + hydrboration oxidation