Question

How is propyne prepared from an
(i) alkylene dihalide (ii) alkylidene dihalide and (iii) tetrahaloalkane?

Answer 1

alkylidene dihalide propyne prepared

Answer 2

Hi Subham,

● Reactions -

(i) Propyne from alkylene dihalide -

1,2-Dibromopropane is treated with alcoholic KOH gives propyne.

CH3-CH(Br)-CH2(Br) + alc.KOH --> CH3-C≡CH + 2KBr + 2H2O

(ii) Propyne from alkylidene dihalide -

1,2-Dibromopropene on heating in presence of zinc dust gives propyne.

CH3-C(Br)=CH(Br) + Zn/∆ --> CH3-C≡CH + Br2

Hope this helped you. Thanks for asking..