How can alkenes be made from alkanes?

1 Answer
Aug 7, 2016

The most common method of making alkenes from alkanes is by halogenation-dehydrohalogenation.


The first step is usually the free radical halogenation of an alkane.

#("CH"_3)_3"C-H" + "Br"_2 stackrelcolor(blue)( hνcolor(white)(m))(→) ("CH"_3)_3"C-Br" + "H-Br"#

Then the alkyl halide is dehydrohalogenated by reacting it with a strong base.

#("CH"_3)_3"C-Br" + "KOH" stackrelcolor(blue)("ethanol/Δ" color(white)(m))(→) ("CH"_3)_2"C=CH"_2 + "KBr" + "H"_2"O"#