Chapter 8 Ochem: Addition Reactions of Alkenes

Hydrohalogenations

Reagents: HX. Treating an Alkene with this reagent gives Markovnikov addition of H and X across the alkene.

Hydrobromination

Reagents: HBr, ROOR. Treating an alkene with these reagents gives anti-Markovnikov addition of H and Br across the alkene

Acid-Cat. Hydration

Reagents: H₃O⁺. Treating an alkene with this reagent Markovnikov addition of of H and OH across the alkene

Oxymercuration-Demurcuration

Reagents: 1) Hg(OAc)_2, H₂O 2) Na BH₄. Treating an alkene with these reagents gives anti-Markovnikov addition of H and OH across the alkene, without any carbocation rearrangement

Hydroboration-Oxidation

Reagents: 1) BH_{3 ,}THF 2) H₂O₂, NaOH. Treating an alkene with these reagents gives anti-Markovnikov addition of H and OH across the alkene. The reaction proceeds exclusively via a syn rearrangements.

Hydrogenation

Reagents: H₂, Pt. Treating an alkene with these reagents gives syn addition of H and H across the alkene.

Bromination

Reagents: Br₂. Treating an alkene with these reagents gives anti addition of Br and Br across the alkene

Halohydrin formation

Reagents: Br₂, H₂O. Treating an alkene with these reagents gives anti addition of Br and OH across the alkene, with the OH group being installed at more substituted position.

Anti Dihydroxylation

Reagents: 1) RCO₃H 2) H₃O⁺. Treating an alkene with a peroxy acid RCO₃H converts the alkene into an epoxide, which is then opened upon treatment with aqueous acid to give a trans-diol.

Syn Dihydroxylation

Reagents: KMnO₄, NaOH, cold. Treating an alkene with these reagents gives syn addition of OH and OH across the alkene.

Ozonolysis

Reagents: 1) O₃ 2) DMS. Ozonolysis of a alkene causes cleavage of C=C bond, giving two compounds, each of which possesses a C=O bond.