OChem Reactions

Alkyne → Alkene (cis)

H₂, Lindlar's catalyst — syn addition gives cis (Z) alkene

Alkyne → Alkene (trans)

Na, NH₃ (dissolving metal) — anti addition gives trans (E) alkene

Alkyne → Ketone/Aldehyde (Markovnikov hydration)

H₂SO₄, H₂O, HgSO₄ — Markovnikov hydration gives ketone (internal alkyne) or aldehyde (terminal)

Alkyne → Aldehyde (anti-Markovnikov)

1) R₂BH 2) H₂O₂, NaOH — hydroboration gives aldehyde at less substituted carbon

Alkene → Alkyne

1) Br₂ 2) xs NaNH₂ 3) H₂O — double elimination of vicinal dibromide

Alkene → Alkane

H₂, Pt/Pd/Ni — catalytic hydrogenation

Alkene → Alcohol (Markovnikov)

H₃O⁺ OR 1) Hg(OAc)₂ 2) NaBH₄, NaOH — OH adds to more substituted carbon

Alkene → Alcohol (anti-Markovnikov)

1) BH₃·THF 2) H₂O₂, NaOH — OH adds to less substituted carbon, syn addition

Alcohol → Alkene

conc. H₂SO₄, heat — E1 elimination, gives Zaitsev product

Alcohol → Alkyl halide

HX OR SOCl₂/pyridine OR PBr₃ OR 1) TsCl/py 2) NaX — converts OH to leaving group

Alkyl halide → Alkene

NaOMe or t-BuOK — E2 elimination with strong base

Ketone/Aldehyde → Alcohol (reduction)

1) LAH 2) H₂O OR NaBH₄, MeOH — reduces C=O to C-OH

Alcohol → Ketone/Aldehyde (oxidation)

H₂CrO₄ OR PCC, CH₂Cl₂ — PCC stops at aldehyde; H₂CrO₄ oxidizes 1° alcohol to carboxylic acid

Alkane → Alkyl halide

Br₂, hν — free radical halogenation at most stable radical position

Alkyl halide → Alcohol

NaOH — backside attack, inversion of configuration

Alkyl halide → Alcohol

H₂O — goes through carbocation, racemization at stereocenter

Alkene → Epoxide

Peroxide or Br₂, H₂O, NaOH

Cis Diol

OsO₄, H₂S

Trans Diol

RCOOOH, H⁺, H₂O

Alkene → Alkyl Halide (Anti Markovnikov)

HBR, ROOR

Alkene → Alkyl Halide (Markovnikov)

HBr

Making a Terminal Alkyne

LDA, H₂O, H⁺

Ozonolysis

O₃, Me₂S