Midterm 3 Mechanisms NIRRS

Alkene + HX (Cl, Br, I) -> Haloalkene

Intermediate: Carbocation (rearrangement possible)
Regiochemistry: Markovnikov (X)
Stereochemistry: Mixed

Alkene + H20 (catalyzed by H2SO4) -> Alcohol

Intermediate: Carbocation (rearrangement possible)
Regiochemistry: Markovnikov (OH)
Stereochemistry: Mixed

Alkene + X2 (Br, Cl, I) -> Vicinal Dihaloalkanes

Intermediate: 3-membered ring halonium ion
Regiochemistry: N/A
Stereochemistry: Anti

Alkene + X2/H20 -> Halohydrin

Intermediate: 3-membered ring halonium ion
Regiochemistry: Markovnikov (OH)
Stereochemistry: Anti

Alkene + BH3, H2O2/HO- ->Alcohol

Intermediate: N/A; 4-membered ring transition state
Regiochemistry: Non-Markovnikov (H on more substituted)
Stereochemistry: Syn

Alkene + OsO4, NAHSO3/H2O -> Vicinal Diols

Intermediate: Cyclic osmate ester
Regiochemistry: N/A
Stereochemistry: Syn

Alkene + O3, (CH3)2S -> Aldehyde + Ketone

Intermediate: Malozonide & Ozonide (C-C bond breaks)
Regiochemistry: N/A
Stereochemistry: N/A

Alkene + H2 (on Pt, Pd, or Ni) -> Alkane

Intermediate: Alkene bonds to metal surface
Regiochemistry: N/A
Stereochemistry: Syn

Alkane + Br2, hv -> Haloalkane

Intermediate: Radical chain process
Regiochemistry: Br ends up on more substituted C atom
Stereochemistry: N/A

Alkene + ROOR, hv, HBr -> Haloalkane

Intermediate: Radical
Regiochemistry: Non-markovnikov
Stereochemistry: Mixed

Haloalkane + Strong base -> Alkene

Intermediate: N/A; anti-periplanar position; E2
Regiochemistry: Zaitsev
Stereochemistry: Determined by anti-periplanar transition state requirement

Vicinal Dihaloalkane + 2NaNH2 -> Internal Alkyne

Intermediate: N/A; Double E2 reaction
Regiochemistry: N/A
Stereochemistry: N/A

Vicinal Dihaloalkane + 3NaNH2, HCl/H2O -> Terminal Alkyne

Intermediate: N/A; Double E2
Regiochemistry: N/A
Stereochemistry: N/A

Internal Alkyne + NaNH2, RCH2X -> Terminal Alkyne

Intermediate: N/A; SN2 reaction; makes C-C bond
Regiochemistry: N/A
Stereochemistry: N/A

Alkyne + Na/NH3 -> Alkene

Intermediate: Radical
Regiochemistry: N/A
Stereochemistry: Anti, E products

Alkyne + H2, Lindlar’s Catalyst -> Alkene

Intermediate: Alkene and H2 adsorb on metal surface
Regiochemistry: N/A
Stereochemistry: Syn, Z products

Alkyne + H2, Pt/Pd/Ni -> Alkane

Intermediate: Adsorption on metal surface
Regiochemistry: N/A
Stereochemistry: N/A

Alkyne + 2HX (Br, Cl, I) -> Geminal Dihaloalkane

Intermediate: HX reacts with both pi bonds
Regiochemistry: Markovnikov
Stereochemistry: N/A

Alkyne + 2X2 (Br, Cl, I) -> Vicinal Tetrahaloalkane

Intermediate: X2 reacts with both pi bonds
Regiochemistry: N/A
Stereochemistry: N/A

Alkyne + (sia)2BH, H2O2/HO- -> Aldehyde/Ketone

Intermediate: N/A; 4-membered ring transition state
Regiochemistry: Non-markovnikov
Stereochemistry: N/A

Alkyne + HgSO4, H2SO4, H2O -> Aldehyde/Ketone

Intermediate: Enol
Regiochemistry: Markovnikov
Stereochemistry: Mixed

Primary Alcohol -> Alkene

Intermediate: Leaving group; E2 reaction
Regiochemistry: Zaitsev
Stereochemistry: N/A

Primary Alcohol + HX -> Haloalkane

Intermediate: N/A; SN2 reaction
Regiochemistry: N/A
Stereochemistry: Inversion

Haloalkane + Nucleophile -> SN2 Products

Intermediate: Nucleophile attacks backside of C-leaving group bond
Regiochemistry: N/A
Stereochemistry: Inversion

Alkene + NBS, hv -> Haloalkene

Intermediate: Allylic radical
Regiochemistry: Most stable alkene product
Stereochemistry: N/A

Secondary/Tertiary Alcohol -> Alkene

Intermediate: Leaving group; E1 reaction
Regiochemistry: Zaitsev
Stereochemistry: N/A

Secondary/Tertiary Alcohol + HX -> Haloalkane

Intermediate: N/A; SN1 reaction
Regiochemistry: N/A
Stereochemistry: Scrambled