Tam
Reactions Michael Review
1. [EA]Addition of HX
Reagents: Alkene + HX
Products: Haloalkane
Regioselectivity: Markovnikov
Stereo selectivity: None
Note: 1,2 Shifts
2. [EA]Acid Catalyzed Addition of H20
Reagents: Alkene + H2SO4 + H2O
Products: Alcohol
Regioselectivity: Markovnikov
Stereo selectivity: None
Note: 1,2 Shifts
3. [EA]Addition of X2
Reagents: Alkene + X2 + CH2Cl2
Products: Dihaloalkane [Racemic or Meso]
Regioselectivity: Markovnikov
Stereo selectivity: Anti
Note:
if original Alkene is Z, then the mixture is racemic
if original Alkene is E, then mixture is meso
This reaction starts with a Bridged Halomonium Ion
3 Resonance Structures
4. [EA]Addition of HOX
Reagents: Alkene + H2O + X2
Products: Halo Hydrin AKA Halo Alcohol [racemic]
Regioselectivity: Markovnikov
Stereo selectivity: Anti
Note: This Reaction starts with a bridged Halomonium Ion
2 Resonance structures
5. [Oxidation]Hydroboration
Reagents: Alkene + BH3 + H2O2 + NaOH
Products: Alcohol (alkane) [Racemic]
Regioselectivity: Non- Markovnikov
Stereo selectivity: Syn
Note: This is the Purdue guy 3 steps 3x
6. [EA & Reduction]Oxymercuration
Reagents: Hg(AcO)2 + H2O + NaBH4
Products: Alcohol(alkane)
Regioselectivity: Markovnikov
Stereo selectivity: Anti
Note: This has the weird hybridized Oxymercuronium intermediate
H2O Attacks more substituted carbon
Protonation to solvent (Water)
Magical Step Hg
7. removes [Oxidation]Ozonolysis
Reagents: Alkene + O3 + (Ch3)2S
Products: Aldehyde + Ketone
Regioselectivity: None
Stereo selectivity: None
Note: Double Bond Cleaved, Carbonyl groups added
Ozone, which has separated charges, attaches to Alkene
Molozonide bonds break, inversion
Reduction & cleavage
8. [Oxidation]Dihydroxylation
Reagents: Alkene + OsO4 + H2O + NaHSO3
Products: Glycol AKA diol [racemic]
Regioselectivity: None
Stereo selectivity: Syn
Note: OsO4 attaches to Alkene
Adding across H bonds
9. [Reduction]Catalyzed Hydrogenation
Reagents: Alkene + H2 + Metal Catalyst
Products: Alkane
Regioselectivity: Dont need to know this mechanism
Stereo selectivity:
Note:
10. [Reduction]Asymmetric Hydrogenation
Reagents: Diynol + BINAP-RuCl3 + H2
Products: Double bond next to OH becomes a single bond
Regioselectivity: None
Stereo selectivity: if (R) BINAP (S) product & Vice-Versa
Note:
Trends
Nucleophile (Ex. Br-) tends to attack more substituted Carbon
All EA are Markovnikov, Hydroboration is not EA and therefore not Markovnikov
5. Hydroboration & 8.Dihydroxylation are syn, 3.Br2, 4. HOBr& 6. Oxymercuration are Anti
2(Acid Catalyzed),5(Hydroboration),6 Oxymercuration create alcohol;
Acid catalyzed is Markovnikov and has no stereo. Remember that Shifts possible
Hydroboration is Non Markovnikov and has syn.
Oxymercuration is Markovnikov and has anti.