Reactions and Transformations of Alkynes and Alkenes

H2, Kindler's Catalyst

Converts alkyne to cis alkene via synaddition.

H2, pt

Reduces alkyne to alkane, removes double bonds.

Na, NH3

Transforms alkyne into alkene.

BH3-THF

Adds OH to least substituted position, removes double bond.

NaOH

Used with BH3-THF for hydroxylation.

H5(OA)2

Adds OH to more substituted position, removes double bond.

NaBH4

Reductive agent in hydroxylation reactions.

T-BuOK

Eliminates Br, forms less substituted alkene.

Her, ROOR

Adds Br to least substituted carbon.

HCl

Adds Cl to more substituted carbon atom.

MeONa

Eliminates H and Br, forms double bond at most substituted.

HBr

Adds Br to most substituted carbon, check for enantiomers.

H3O+

Adds OH to most substituted carbon, check for enantiomers.

NaOEt

Strong base and nucleophile, facilitates Sn2 or E2.

NaNH2

Deprotonates H from triple bond, facilitates further reactions.

O3

Used in ozonolysis to form ketones.

Zn

Reductive agent in ozonolysis.

HgSO4

Adds ketone to more substituted carbon of triple bond.

Br2

Adds Br2 across double bonds, antiaddition.

Br2, H2O

Adds Br to least substituted, OH to more substituted.

Br2, light

Adds one Br to most substituted carbon.

NBS, light

Forms resonance stabilized radical, bromination at both locations. Adds a Br..

Conc. H2SO4

Removes OH, adds double bond to more substituted carbons.