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