Alkene and Alkyne Reactions

Halohydrin Formation of Alkenes

Reagents: X2, H20

Addition of OH group and halogen atom across alkene

OH goes in most substituted position

Hydrogenation of an alkene

Reagents: H2, Pt

• Syn addition of H

Hydrohalogenation of alkene

Reagents: HBR

• (adding ROOR produces antimarkovnikov product)

• addition of halogen and H across alkene

• forms a carbocation intermediate

Hydration of alkene

Reagents: H3O+/dilute H2SO4

• Markovnikov addition of OH and H across alkene

Hydroboration - Oxidation of alkene

Reagents: 1) BH3, 2) NaOH, 3) H2O2

• Antimarkovnikov and sun addition of OH and H across alkene

Halogenation of alkene

• Addition of 2 Halogen atoms across alkene

Antidihydroxylation of alkene

Reagents: 1) RCO3H, 2) H3O+

• Forms epoxide intermediate

• Addition of 2OH across alkene

Syn dihydroxylation of alkene

Reagents: KMnO4, and NaOH, H2O

• Syn addition of 2OH across alkene

Ozonolysis of alkene

Reagents: 1) O3, 2) DMS

• cleaves carbon-carbon bond to form either ketone or aldehyde FG

Reduction reactions of alkynes

Reduces alkyne to either cis or trans alkene or all the way to alkane

• cis alkene reagents: H2 Lindlar catalyst

• trans alkene reagents: Na, NH3 (l)

• alkane reagents: H2, Pt

Hydrohalogenation of Alkynes

Reagents: either HX or xs HX (xs goes to alkane)

• similar to alkene

Hydration of alkyne

Reagents: H2SO4, H2O, & HgSO4

• Markovnikov addition of OH to create ketone group enol and ketone are tautomers formed under acidic conditions

Hydroboration - Oxidation of Alkynes

Reagents: 1) 9-BBN, 2) H2O2, 3) NaOH

• Anti-markovnikov addition of OH to create aldehyde group

• enol and aldehyde are tautomers formed under basic conditions

Halogenation of alkyne

Reagents: Br2 or xs Br2

• Addition of halogen atoms

Ozonolysis of alkynes

Reagents: 1) O3, 2) H2O

• Cleaves alkyne to produce carboxylic acid or Co2

• If alkyne is internal, 2 carboxylic FG are made

• If alkyne is terminal, a carboxylic FG is made plus CO2