Alkene Reactions

Hydrohalogenation

HX (HCl, HBr, HI)

Radical hydrobromination

HBr, ROOR (peroxides)

Acid-catalyzed hydration

H₂SO₄, H₂O

Oxymercuration–demercuration

1) Hg(OAc)₂, H₂O 2) NaBH₄

Alkoxymercuration–demercuration

1) Hg(OAc)₂, ROH 2) NaBH₄

Hydroboration–oxidation

1) BH₃ 2) H₂O₂, ⁻OH

Halogenation

Br₂ or Cl₂

Halohydrin formation

Br₂, H₂O

Haloether formation

Br₂, ROH

Epoxidation

mCPBA

Anti dihydroxylation

1) mCPBA 2) H₃O⁺

Syn dihydroxylation (OsO₄)

OsO₄, H₂O₂ (or cat. OsO₄, NMO)

Syn dihydroxylation (KMnO₄)

KMnO₄, ⁻OH (cold, dilute)

KMnO₄ cleavage

KMnO₄ (warm, concentrated)

Ozonolysis

1) O₃ 2) Me₂S

Diol cleavage

1) OsO₄, NMO 2) NaIO₄

Catalytic hydrogenation

H₂, Pd/C

Dihalocarbene cyclopropanation

CHCl₃, NaOH

Simmons–Smith cyclopropanation

CH₂I₂, Zn(Cu)

HX in CH₂Cl₂

Markovnikov alkyl halide

HBr, ROOR in hexane

Anti-Markovnikov alkyl bromide

H₂SO₄ in H₂O

Markovnikov alcohol

1) Hg(OAc)₂ in H₂O/THF 2) NaBH₄

Markovnikov alcohol (no rearrangement)

1) Hg(OAc)₂ in ROH 2) NaBH₄

Markovnikov ether

1) BH₃ in THF 2) H₂O₂, NaOH in H₂O

Anti-Markovnikov alcohol

Br₂ in CH₂Cl₂

Vicinal dihalide

Br₂ in H₂O

Halohydrin (OH on more substituted C)

Br₂ in MeOH

Halo ether (OR on more substituted C)

mCPBA in CH₂Cl₂

Epoxide

1) mCPBA in CH₂Cl₂ 2) H₃O⁺ in H₂O

trans-1,2-diol

OsO₄, NMO in H₂O/t-BuOH

cis-1,2-diol

Cold, dilute KMnO₄, NaOH in H₂O

cis-1,2-diol

Warm, concentrated KMnO₄ in H₂O

Ketones, carboxylic acids, CO₂ (C=C cleaved)

1) O₃ in CH₂Cl₂, −78 °C 2) Me₂S

Aldehydes and ketones (C=C cleaved)

1) OsO₄, NMO in H₂O/t-BuOH 2) NaIO₄

Aldehydes and ketones (C=C cleaved)

H₂, Pd/C in EtOH

Alkane

CHCl₃ with 50% aqueous NaOH

gem-Dichlorocyclopropane

CH₂I₂, Zn(Cu) in Et₂O

Cyclopropane (adds CH₂)

Is hydrohalogenation syn, anti, or neither?

Neither

Is radical hydrobromination syn, anti, or neither?

Neither

Is acid-catalyzed hydration syn, anti, or neither?

Neither

Is oxymercuration–demercuration syn, anti, or neither?

Anti

Is alkoxymercuration–demercuration syn, anti, or neither?

Anti

Is hydroboration–oxidation syn, anti, or neither?

Syn

Is halogenation syn, anti, or neither?

Anti

Is halohydrin formation syn, anti, or neither?

Anti

Is haloether formation syn, anti, or neither?

Anti

Is epoxidation syn, anti, or neither?

Syn

Is anti dihydroxylation syn, anti, or neither?

Anti

Is syn dihydroxylation (OsO₄) syn, anti, or neither?

Syn

Is syn dihydroxylation (KMnO₄) syn, anti, or neither?

Syn

Is KMnO₄ cleavage syn, anti, or neither?

Neither (C=C cleaved)

Is ozonolysis syn, anti, or neither?

Neither (C=C cleaved)

Is diol cleavage syn, anti, or neither?

Neither (C=C cleaved)

Is catalytic hydrogenation syn, anti, or neither?

Syn

Is dihalocarbene cyclopropanation syn, anti, or neither?

Syn

Is Simmons–Smith cyclopropanation syn, anti, or neither?

Syn

Intermediate in hydrohalogenation?

Carbocation

Intermediate in radical hydrobromination?

Carbon radical

Intermediate in acid-catalyzed hydration?

Carbocation

Intermediate in oxymercuration–demercuration?

Mercurinium ion

Intermediate in alkoxymercuration–demercuration?

Mercurinium ion

Intermediate in hydroboration–oxidation?

None (concerted); trialkylborane before oxidation

Intermediate in halogenation?

Halonium ion

Intermediate in halohydrin formation?

Halonium ion

Intermediate in haloether formation?

Halonium ion

Intermediate in epoxidation?

None (concerted)

Intermediate in anti dihydroxylation?

Epoxide (then protonated epoxide)

Intermediate in syn dihydroxylation (OsO₄)?

Cyclic osmate ester

Intermediate in syn dihydroxylation (KMnO₄)?

Cyclic manganate ester

Intermediate in KMnO₄ cleavage?

1,2-diol

Intermediate in ozonolysis?

Molozonide, then ozonide

Intermediate in diol cleavage?

1,2-diol, then cyclic periodate ester

Intermediate in catalytic hydrogenation?

Alkene and H bound to the metal surface

Intermediate in dihalocarbene cyclopropanation?

Dichlorocarbene (:CCl₂)

Intermediate in Simmons–Smith cyclopropanation?

Zinc carbenoid (ICH₂ZnI)