ochem rxns

1) Cl₂, H₂O 2) NaOH, H₂O

Alkene to Epoxide

• has halohydrin intermediate (where OH goes to the MORE substituted carbon & Cl goes to the LESS substituted carbon)

• stereochem: anti addition in the halohydrin step, followed by an SN2 inversion, then epoxide

H₃PO₄

Alcohol to Alkene

• 2° or 3° alcohols

• Gives Zaitsev alkene (more substituted)

• Proceeds via E1

HX

Alkene to Haloalkane

• regiochem: Addition of X at MarkovNikov position

HBr, ROOR (peroxide)

Alkene to Haloalkane

• regiochem: Anti-MarkovNikov additon to pi bond

• Br adds to the LESS substituted carbon

• H adds to the MORE substituted carbon

H₃O⁺/H₂O

Alkene to Alcohol

• regiochemistry: markovnikov addition to a pi bond

1)Hg(OAc)₂, H₂O 2)NaBH₄

Alkene to Alcohol

• regiochem: addition of Alcohol at MarkovNikov

1) BH₃ 2) H₂O₂, NaOH

Alkene to Alcohol

• regiochemistry: anti-MarkovNikov addition to pi bond

• stereochem: syn-addition

H₂/Pd, Pt, Ni

Alkene to Alkane

• stereochemistry: syn-addition

X₂ (ex. Br₂)

Alkene to Vicinal Dihaloalkane

• halogenation to both double bond positions

• stereochem: anti-addition (the two halogens end up on opposite faces of the alkene)

X₂, H₂O (ex. Br₂)

Alkene to Halohydrin

• halogenation at Anti-MarkovNikov Position (X goes to the LESS substituted carbon)

• adds Alcohol at MarkovNikov Postion (OH goes to the MORE substituted carbon)

• stereochem: anti-addition (OH and X end up on opposite faces)

1) OsO₄ 2) NaHSO₃

Alkene to Vicinal Diol

• regiochem for first step: syn-addition

• Adds Alcohol to both double bond positions

• will always give a vicinal diol with the two OH groups on the same face (same stereochem)

1) O₃ 2) DMS [same as (CH₃)₂S ]

Alkene to Aldehyde/Ketone

• cleave carbon carbon bond at Double Bond site and adds Oxygen to both openings

• If an alkene carbon has at least one H → it becomes an aldehyde

• If an alkene carbon has no Hs (only carbons attached) → it becomes a ketone

MCPBA

Alkene to Epoxide

• stereochem: syn addition

• preserves alkene geometry:

cis alkene → cis epoxide

trans alkene → trans epoxide

H₂SO₄, HgSO₄

Alkyne to Ketone

• regiochem: Adds Ketone at MarkovNikov Position

• only forms aldehyde in the case of acetylene (ethyne, HC≡CH)

1) BH₃ 2)H₂O₂, NaOH

Alkyne to Aldehyde/Ketone

• Terminal alkyne (R–C≡CH) → Aldehyde

• Internal alkyne (R–C≡C–R′) → Ketone(s)

PCC or DMP or Swern Oxidation = 1) oxalyl chloride, DMSO; 2) tertiary amine

Alcohol to Aldehyde/Ketone

• for 1° alcohol → aldehyde

• for 2° alcohol → ketone

• for 3° alcohol → no reaction

H₂CrO₄

Alcohol to Aldehyde to Carboxylic Acid

HIO₄

Vicinal Diols into Aldehyde/Ketone

• cleaves CC bonds

• The two OH groups must be vicinal AND syn (cis)

• If a diol carbon has at least one H → aldehyde

• If it has no H (only carbons attached) → ketone

1) LiAlH₄ 2) H₂O

Epoxide to Alcohol

H₂O/H₃O⁺

Epoxide to Vicinal Diol

• The two OH groups end up anti (trans) to each other

TMSCl + pyr

Alcohol to Silyl Ether

TBAF

Silyl Ether to Alcohol

NaOR

Haloalkane to Alkene

• works w 2° or 3° haloalkane

• Regiochemistry: follows Zaitzev’s rules so the more substituted alkene predominates

• Stereochem: requirement for the X and H to be eliminated with anti-periplanar geometry (E2 rxn)

• works for all haloalkanes except methyl, but a bulky (non-nucleophilic) base must be used for 1° haloalkane

H₂/Lindlars cat.

Alkyne to Alkene

• Stereochemistry: gives cis-alkenes as products

H₂/Pd, Pt, or Ni

Alkyne to Alkane

Na/NH₃

Alkyne to Alkene

• Stereochemistry: gives trans-alkenes as products

X₂, hv or heat

Alkane to Haloalkane

• regiochem: Reactivity of C–H bonds follows 3° > 2° > 1°

• stereochem: Racemic if chiral

H₂O, acid

Haloalkane into Alcohols

• Works for 2° and 3° haloalkanes

• stereochem: racemic if chiral

• SN1 mechanism

HX or SOCl₂ (+ base) or PBr₃

Alcohol to Haloalkane

• works for methyl, 1°, and 2° haloalkanes

• mechanism: SN2 → inversion

NBS

Alkene to Allylic Halides

• Regiochemistry: the product with the more substituted alkene predominates

ROH/acid

Alkene to Ethers

• Works for 2° and 3° haloalkanes

• regiochem: Markovnikov addition

NaOH

Haloalkane to Alcohol

• Works well for methyl and 1° haloalkanes

• Inversion (SN2)

NaOR

Haloalkane to Ether

• Works well for methyl and 1° haloalkanes

• Inversion of configuration at that carbon (SN2)

ROH

Haloalkane to Ether

• Works for 2° and 3° haloalkanes

HI

Ether to Haloalkane

• The ether oxygen is protonated

• Makes a good leaving group (ROH⁺)

1) (sia)₂BH, 2) H₂O₂, NaOH

Alkyne to Aldehyde/Ketone

• regiochem: anti-Markovnikov addition to pi bond

• Terminal alkyne (R–C≡CH) → Aldehyde

• Internal alkyne (R–C≡C–R′) → Ketone(s)

NH₃; result: NH₂ on the less substituted carbon & OH on the more substituted carbon

Epoxide to Vicinal Aminoalcohol

• regiochem: Attack at the LESS substituted carbon

  • NH₃ is a nucleophile

  • SN2-like behavior dominates

NaNH₂/NH₃

Vicinal Dihaloalkane to Alkyne

2X₂

Alkyne to Vicinal Tetrahaloalkane

• 1 equivalent X₂ → trans dihaloalkene

• 2 equivalents X₂ → tetrahaloalkane

2HX; result:

• X adds to the more substituted carbon

• H adds to the less substituted carbon

• The second HX adds the same way as the first

Alkyne to Geminal Dihaloalkane

• regiochem: markovnikov addition to pi bond

NaN₃

Haloalkane to Alkyl Azides

• works for methyl, 1°, and 2° haloalkanes

• reaction type: SN2

• stereochem: inversion

• result: N₃ replaces X at the same carbon

NHR₂

Haloalkane to Amine

• works for methyl, 1°, and 2° haloalkanes

• rxn type: SN2 → inversion

NaSR

Haloalkane to Thioether

• works for methyl, 1°, and 2° haloalkanes

• rxn type: SN2 → inversion

NaSH

Haloalkane to Thiol

• works for methyl, 1°, and 2° haloalkanes

• rxn type: SN2 → inversion

NaCN

Haloalkane to Nitrile

• works for methyl, 1°, and 2° haloalkanes

• carbon carbon bond forms

• rxn type: SN2 → inversion

NaC≡CR

Haloalkane to Alkyne

• works for methyl and 1° haloalkanes

• carbon carbon bond forms

• rxn type: SN2 → inversion