When haloalkane or alkyl halide with a β – hydrogen atom is heated with alcoholic solution of potassium hydroxide (alc. KOH), the OH– ion acts as a base and eliminate an electron from β – carbon atom then this elimination is known as β – elimination. There is also a simultaneous elimination of halogen atom from a carbon. As a result, an alkene is formed.
For Example:
This reaction is also called dehydrohalogenation.
