Home O2 O3 X2 H2O2 NaOCl CrO3 or any Cr2 PCC KMnO4 OsO4 Ag2O HClO4 HIO4 Reducing Agents H2 Li Na K NaBH4 LiAlH4 Reduction of alkynes to trans alkenes Na and liq. NH3 (sometimes with EtOH) Two Hs added to opposite sides of alkene Reduction of Alkynes to Cis alkenes H2 and Lindlar's catalyst (Pd, quinoline, CaCO3, Pb(OAC)2) Two Hs added to same side of alkene Alkynes are more reactive than alkenes and Lindlar’s is too weak for alkenes Reduction of alkenes to alkanes (Catalytic Hydrogenation) H2 excess, catalyst (Ni, Pd, Pt, Pd/C) Exothermic Always syn addition of Hs Reduction of alkynes to alkanes (Catalytic Hydrogenation) H2 excess, catalyst (Ni, Pd, Pt) 4 Hs added Stability of Alkenes More substituted is more stable Trans is more stable than cis Reduction of alkyl halides to alkanes w/LAH Also written LiAlH4 SN2 rxn X is substituted with H X = I > Br > Cl (not F) Rate of rxn : Me > 1 > 2 (not 3) Epoxidation of alkenes w/ Peracids Alkene forms epoxide Rxn is stereospecific (if it starts cis the epoxide ends in cis) Weakest O-H bond from peroxide moves 1 step rxn no intermediate Common peracids: MCPBA and MMPP Oxidative Cleavage of Alkenes O3 H2O, CH3SCH3, PPh3 Cut in half at alkene and add =O to make aldehyde or ketones Oxidative cleavage of Alkynes (Ozonolysis) O3 H2O, CH3SCH3, PPh3 Internal Alkyne: cut in half and make two carboxylic acids Terminal Alkyne: cut in half and make carboxylic acid and CO2 PCC Oxidation (Pyridinium chlorochromate) Soluble in organic solvent Stops at aldehyde and doesn't go to COOH even with primary OH O becomes double bonded and H attaches to C Oxidation of Alcohols Primary [O] aldehyde [O] carboxylic acid Secondary [O] ketone Tertiary [O] no rxn [O] conditions: Na2Cr2O7 or K2Cr2O7 over H2SO4, H2O And H2CrO4 over acetone (jones reagent) Anti - 1,2 - dihydroxylation Peracid H+ or OH- in H2O OH added to opposite sides of C-C bond First peracid makes an epoxide where R1 and R3 stay cis so dashed Then second step opens ring with OH on straight bonds If cyclo then racemic mixture of OH on dashed and wedged Syn - 1,2 - dihydroxylation 3 conditions: Cold KMnO4 over OH- and H2O Cat OsO4, NMO 2) NaHSO3, H2O OsO4 2) NaHSO3, H2O OH added to straight bonds on same side of C-C bond Needs to be rotated 180 for final product where OH is across from each other Chapter 13 Breaking into radicals : homolytic cleavage and endothermic Radicals are sp3, trigonal planar, 120, empty p-orbital Most stable to least stable: 3 > 2 > 1 > methyl Why? Hyperconjugation (R groups stabilize radical C) Induction (electrons flow from sp3 C to sp2 C) How do radicals react Radicals attack sigma bonds: radical hits bond and takes H Radicals attack pi bonds: radical hits bond and attaches to C Radicals attack radicals: coupling exothermic Alkanes w/ Halogens Exothermic R-H + X2 with light and heat makes R-X + HX X2 is either Cl or Br Alkane w/ Cl2 Initiation: Cl-Cl breaks to two Cl rad Propagation: Cl rad + alkane making Cl-H and alkane rad Alkane rad + Cl-Cl making alkane with one less H and Cl attached Chlorination of Higher Alkanes Cl2 with light heat # of signals is types of products Not very regioselectivity Bromination of Higher Alkanes Br2 with light heat Very regioselective Br goes to most sub C Radical Stability Allylic radical > 3 > 2 > 1 > me > vinyl =. Stereochemistry of radical Halogen Cl rad + alkane Cl & Br can be added to top or bottom on straight bond creating enantiomers or diasteromers Allylic Substitution If it is alkene + X2 at high concentration, low temp over a non polar solvent then it is a vicinal dihalide ( X to both previous alkene Cs) If it is alkene + X2 at low concentration, high temp then one X subs on sp3 C attached to double bond and the bond stays and HX is made

O2 O3 X2 H2O2 NaOCl CrO3 or any Cr2 PCC KMnO4 OsO4 Ag2O HClO4 HIO4 Reducing Agents H2 Li Na K NaBH4 LiAlH4 Reduction of alkynes to trans alkenes Na and liq. NH3 (sometimes with EtOH) Two Hs added to opposite sides of alkene Reduction of Alkynes to Cis alkenes H2 and Lindlar's catalyst (Pd, quinoline, CaCO3, Pb(OAC)2) Two Hs added to same side of alkene Alkynes are more reactive than alkenes and Lindlar’s is too weak for alkenes Reduction of alkenes to alkanes (Catalytic Hydrogenation) H2 excess, catalyst (Ni, Pd, Pt, Pd/C) Exothermic Always syn addition of Hs Reduction of alkynes to alkanes (Catalytic Hydrogenation) H2 excess, catalyst (Ni, Pd, Pt) 4 Hs added Stability of Alkenes More substituted is more stable Trans is more stable than cis Reduction of alkyl halides to alkanes w/LAH Also written LiAlH4 SN2 rxn X is substituted with H X = I > Br > Cl (not F) Rate of rxn : Me > 1 > 2 (not 3) Epoxidation of alkenes w/ Peracids Alkene forms epoxide Rxn is stereospecific (if it starts cis the epoxide ends in cis) Weakest O-H bond from peroxide moves 1 step rxn no intermediate Common peracids: MCPBA and MMPP Oxidative Cleavage of Alkenes O3 H2O, CH3SCH3, PPh3 Cut in half at alkene and add =O to make aldehyde or ketones Oxidative cleavage of Alkynes (Ozonolysis) O3 H2O, CH3SCH3, PPh3 Internal Alkyne: cut in half and make two carboxylic acids Terminal Alkyne: cut in half and make carboxylic acid and CO2 PCC Oxidation (Pyridinium chlorochromate) Soluble in organic solvent Stops at aldehyde and doesn't go to COOH even with primary OH O becomes double bonded and H attaches to C Oxidation of Alcohols Primary [O] aldehyde [O] carboxylic acid Secondary [O] ketone Tertiary [O] no rxn [O] conditions: Na2Cr2O7 or K2Cr2O7 over H2SO4, H2O And H2CrO4 over acetone (jones reagent) Anti - 1,2 - dihydroxylation Peracid H+ or OH- in H2O OH added to opposite sides of C-C bond First peracid makes an epoxide where R1 and R3 stay cis so dashed Then second step opens ring with OH on straight bonds If cyclo then racemic mixture of OH on dashed and wedged Syn - 1,2 - dihydroxylation 3 conditions: Cold KMnO4 over OH- and H2O Cat OsO4, NMO 2) NaHSO3, H2O OsO4 2) NaHSO3, H2O OH added to straight bonds on same side of C-C bond Needs to be rotated 180 for final product where OH is across from each other Chapter 13 Breaking into radicals : homolytic cleavage and endothermic Radicals are sp3, trigonal planar, 120, empty p-orbital Most stable to least stable: 3 > 2 > 1 > methyl Why? Hyperconjugation (R groups stabilize radical C) Induction (electrons flow from sp3 C to sp2 C) How do radicals react Radicals attack sigma bonds: radical hits bond and takes H Radicals attack pi bonds: radical hits bond and attaches to C Radicals attack radicals: coupling exothermic Alkanes w/ Halogens Exothermic R-H + X2 with light and heat makes R-X + HX X2 is either Cl or Br Alkane w/ Cl2 Initiation: Cl-Cl breaks to two Cl rad Propagation: Cl rad + alkane making Cl-H and alkane rad Alkane rad + Cl-Cl making alkane with one less H and Cl attached Chlorination of Higher Alkanes Cl2 with light heat # of signals is types of products Not very regioselectivity Bromination of Higher Alkanes Br2 with light heat Very regioselective Br goes to most sub C Radical Stability Allylic radical > 3 > 2 > 1 > me > vinyl =. Stereochemistry of radical Halogen Cl rad + alkane Cl & Br can be added to top or bottom on straight bond creating enantiomers or diasteromers Allylic Substitution If it is alkene + X2 at high concentration, low temp over a non polar solvent then it is a vicinal dihalide ( X to both previous alkene Cs) If it is alkene + X2 at low concentration, high temp then one X subs on sp3 C attached to double bond and the bond stays and HX is made

Oxidizing Agents

H2O2

NaOCl

CrO3 or any Cr2

PCC

KMnO4

OsO4

Ag2O

HClO4

HIO4

Reducing Agents

NaBH4

LiAlH4

Reduction of alkynes to trans alkenes

Na and liq. NH3 (sometimes with EtOH)

Two Hs added to opposite sides of alkene

Reduction of Alkynes to Cis alkenes

H2 and Lindlar's catalyst (Pd, quinoline, CaCO3, Pb(OAC)2)

Two Hs added to same side of alkene

Alkynes are more reactive than alkenes and Lindlar’s is too weak for alkenes

Reduction of alkenes to alkanes (Catalytic Hydrogenation)

H2 excess, catalyst (Ni, Pd, Pt, Pd/C)

Exothermic

Always syn addition of Hs

Reduction of alkynes to alkanes (Catalytic Hydrogenation)

H2 excess, catalyst (Ni, Pd, Pt)

4 Hs added

Stability of Alkenes

More substituted is more stable

Trans is more stable than cis

Reduction of alkyl halides to alkanes w/LAH

Also written LiAlH4

SN2 rxn

X is substituted with H

X = I > Br > Cl (not F)

Rate of rxn : Me > 1 > 2 (not 3)

Epoxidation of alkenes w/ Peracids

Alkene forms epoxide

Rxn is stereospecific (if it starts cis the epoxide ends in cis)

Weakest O-H bond from peroxide moves

1 step rxn no intermediate

Common peracids: MCPBA and MMPP

Oxidative Cleavage of Alkenes

O3
H2O, CH3SCH3, PPh3

Cut in half at alkene and add =O to make aldehyde or ketones

Oxidative cleavage of Alkynes (Ozonolysis)

O3
H2O, CH3SCH3, PPh3

Internal Alkyne: cut in half and make two carboxylic acids

Terminal Alkyne: cut in half and make carboxylic acid and CO2

PCC Oxidation (Pyridinium chlorochromate)

Soluble in organic solvent

Stops at aldehyde and doesn't go to COOH even with primary OH

O becomes double bonded and H attaches to C

Oxidation of Alcohols

Primary [O] aldehyde [O] carboxylic acid

Secondary [O] ketone

Tertiary [O] no rxn

[O] conditions:

Na2Cr2O7 or K2Cr2O7 over H2SO4, H2O

And H2CrO4 over acetone (jones reagent)

Anti - 1,2 - dihydroxylation

Peracid
H+ or OH- in H2O

OH added to opposite sides of C-C bond

First peracid makes an epoxide where R1 and R3 stay cis so dashed

Then second step opens ring with OH on straight bonds

If cyclo then racemic mixture of OH on dashed and wedged

Syn - 1,2 - dihydroxylation

3 conditions:

Cold KMnO4 over OH- and H2O

Cat OsO4, NMO 2) NaHSO3, H2O

OsO4 2) NaHSO3, H2O

OH added to straight bonds on same side of C-C bond

Needs to be rotated 180 for final product where OH is across from each other

Chapter 13

Breaking into radicals : homolytic cleavage and endothermic

Radicals are sp3, trigonal planar, 120, empty p-orbital

Most stable to least stable: 3 > 2 > 1 > methyl

Why? Hyperconjugation (R groups stabilize radical C)

Induction (electrons flow from sp3 C to sp2 C)

How do radicals react

Radicals attack sigma bonds: radical hits bond and takes H

Radicals attack pi bonds: radical hits bond and attaches to C

Radicals attack radicals: coupling exothermic

Alkanes w/ Halogens

Exothermic

R-H + X2 with light and heat makes R-X + HX

X2 is either Cl or Br

Alkane w/ Cl2

Initiation: Cl-Cl breaks to two Cl rad

Propagation:

Cl rad + alkane making Cl-H and alkane rad

Alkane rad + Cl-Cl making alkane with one less H and Cl attached

Chlorination of Higher Alkanes

Cl2 with light heat

# of signals is types of products

Not very regioselectivity

Bromination of Higher Alkanes

Br2 with light heat

Very regioselective Br goes to most sub C

Radical Stability

Allylic radical > 3 > 2 > 1 > me > vinyl =.

Stereochemistry of radical Halogen

Cl rad + alkane

Cl & Br can be added to top or bottom on straight bond creating enantiomers or diasteromers

Allylic Substitution

If it is alkene + X2 at high concentration, low temp over a non polar solvent then it is a vicinal dihalide ( X to both previous alkene Cs)

If it is alkene + X2 at low concentration, high temp then one X subs on sp3 C attached to double bond and the bond stays and HX is made.

Allylic Chloranation (shell process)

Alkene + Cl2 and 400 degrees makes alkene w/ Cl attached on previous CH3 + HCl

Initiation: Cl-Cl breaking to 2 radicals

Propagation:

alkene + Cl rad making alkene rad + HCl

Alkene rad + Cl-Cl making alkene+Cl and Cl rad

Alkene radicals are resonance stabilized

Allylic Bromination

May use NBS dont be scared same as chlorination

Anti-Mark addition of HBr to Alkenes

Alkene + HBr with peroxide (ROOR) and light makes H go to C with less H

Initiation:

peroxide breaks at O-O bond with light

Peroxide radical RO breaks H-Br making Br rad

Propagation:

Alkene + Br rad makes rad with Br attached

Rad with Br + H-Br makes final product