Dihaloalkane Isomerism

Dihaloalkane Isomerism: When dihaloalkanes are treated with excess of alcoholic KOH, alkynes are formed by the elimination of two molecules of halogen acids. Dihaloalkanes are of two types (i) 1,2-dihalides or vicinal dihalides (ii) 1,1-dihalides or gem dihalides.

Dihaloalkane shows two types of isomerism:

1. Jem-dihalo: In this isomerism, two halogen atoms are attached together with the same carbon atom.
2. Vicinal-dihalo: Two halogen atoms are attached together with the different carbon atoms.

The reactivity of haloalkanes goes as follows: Iodoalkone > Bromoalkane > Chloroalkane

• Difluoro butane (C₄H₈F₂) has 10 isomers