Alkenes

Hydration Reaction

• Starting Molecule: Alkene (C=C double bond).

• Reagents: Water (H₂O), sometimes with a dilute acid like H₂SO₄.

• Reaction Details: Adds H₂O across the double bond in an alkene, forming an -OH group (Markovnikov addition).

Dehydration Reaction

• Starting Molecule: Alcohol (R-OH).

• Reagent: Concentrated strong acids (H₂SO₄ or H₃PO₄).

• Reaction Details: Removes -OH, forming a double bond (alkene) or another unsaturated product.

Hydrohalogenation (Halogenation of Alkenes)

• Starting Molecule: Alkene (C=C double bond).

• Reagents: HX (e.g., HCl, HBr, HI).

• Reaction Details: Markovnikov addition of halogen across the double bond.

Bromination Reaction

• Starting Molecule: Alkene (C=C double bond).

• Reagent: Br₂.

• Reaction Details: Bromine adds in a trans (anti) fashion across the double bond.

Hydrohalogenation with Peroxides

• Starting Molecule: Alkene (C=C double bond) and presence of a halide source (H-X).

• Reagents: HX (e.g., HBr) with ROOR (peroxide).

• Reaction Details: Anti-Markovnikov addition via radical mechanism.

Halohydrin Formation

• Starting Molecule: Alkene (C=C double bond).

• Reagents: Halogen (X₂) with water (H₂O).

• Reaction Details: One carbon of the double bond gets X, and the other gets -OH.

Acid-Catalyzed Hydration

• Starting Molecule: Alkene (C=C double bond).

• Reagents: Water with an acid catalyst (e.g., dilute H₂SO₄).

• Reaction Details: Adds H₂O to form an -OH (Markovnikov addition).

Oxymercuration

• Starting Molecule: Alkene (C=C double bond).

• Reagents: Mercury(II) acetate (Hg(OAc)₂) with water, followed by NaBH₄.

• Reaction Details: Markovnikov addition forming an -OH and H product.

Hydroboration/Oxidation

• Starting Molecule: Alkene (C=C double bond).

• Reagents: Borane (BH₃) or B₂H₆, followed by H₂O₂ and NaOH.

• Reaction Details: Anti-Markovnikov addition with syn addition of -OH and H.

Hydrogenation

• Starting Molecule: Alkene or alkyne (C=C or C≡C).

• Reagents: H₂ gas with Pd/C catalyst.

• Reaction Details: Adds H-H across the double bond, canceling it out.

Epoxidation

• Starting Molecule: Alkene (C=C double bond).

• Reagent: meta-Chloroperoxybenzoic acid (mCPBA).

• Reaction Details: Forms a three-membered epoxide (O triangle) across the double bond.

Dihydroxylation

• Starting Molecule: Alkene (C=C double bond).

• Reagents: OsO₄ or KMnO₄.

• Reaction Details: Adds two -OH groups across the double bond on the same side (syn addition).

Ozonolysis

• Starting Molecule: Alkene (C=C double bond).

• Reagents: O₃ (ozone), followed by a reducing agent such as Zn or (CH₃)₂S.

• Reaction Details: Cleaves the double bond, forming carbonyl-containing products.

Oxidative Cleavage

• Starting Molecule: Alkene (C=C double bond).

• Reagents: KMnO₄ with acid (e.g., H₂SO₄).

• Reaction Details: Cleaves into carboxylic acids or ketones, depending on substitution of the double bond carbon.

Diol Reaction

• Starting Molecule: Alkene (C=C double bond).

• Reagents: OsO₄ or KMnO₄.

• Reaction Details: Adds -OH groups across the double bond.

Addition with Carbene / Cyclopropanation Reaction

• Starting Molecule: Alkene (C=C double bond), forming a three-membered ring.

• Reagents: Diazomethane (CH₂N₂) or Zn/Cu with halocarbon (e.g., CH₂I₂).

• Reaction Details: Forms a three-membered ring (triangle) across the double bond.