Reaksi Alkuna

Reaksi adisi

Y Z

C ≡ C + YZ → C=C YZ→

C C

Y Z

1. Adisi hidrogen

H H

C≡C 2H 2→

C C

alkuna H H

alkana

H

Na or Li, NH3 C=C anti

H

C≡ C

H2 C=C syn

Lindlar catalyst H H

Contoh :

CH3 C≡C CH3 2H2 , Ni→

CH3CH2CH2CH3

2-Butyne n-Butane

H C2H5

Na , NH3(liq) C=C

C2H5 H

C2H5C ≡ CC2H5 trans -3-hexene

3-Hexyne C2H5 C2H5

H2 C=C

Lindlar catalyst H H

Cis -3-hexene

2. Adisi halogen

X X

C≡C x2→

C=C x2→

C C x2 = Cl2 , Br2

X X X X

Contoh :

Br Br

CH3C ≡ CH Br2→

CH3 C = CH Br2→

CH3 C CH

Br Br Br Br

3. Adisi hidrogen halida

H X

C ≡ C HX→

C = C HX→

C C HX = HCL , HBr , HI

H X H X

Contoh :

I

CH3C ≡ CH HCL→

CH3C = CH2 HI→ CH3 C CH3

Cl Cl

4. Adisi air hidrasi

H

C ≡ C + H2O H 2SO 4 , HgSO 4→

C = C C C

H OH H O

Contoh :

H

H C ≡ C H + H2O H 2SO 4 , HgSO 4→

H C C H

H O

Acetaldehyde

H H

CH3 C ≡ C H + H2O H 2SO 4 , HgSO 4→

H C C C H

H O H

Acetone

Reaksi Asam

C ≡ C H + base C ≡ C :-

5. Pembentukan asetil logam

Contoh :

CH3 CH C ≡ C H + LiNH2 ether→ CH3 CH C ≡ C : -Li+ + NH3

CH3 CH3

Lithium isopropylacetylide