E1 reaction

An E1 reaction is a type of elimination reaction in organic chemistry where a pair of atoms or groups are removed from a molecule. This process typically transforms saturated compounds (with single carbon-carbon bonds) into unsaturated compounds (with double or triple carbon-carbon bonds).1

In an E1 reaction, the rate of the reaction depends only on the concentration of the substance being transformed. This is in contrast to an E2 reaction, where the rate depends on the concentrations of both the substrate and the eliminating agent. E1 reactions proceed in a stepwise manner, often involving a carbanionic intermediate, which can lead to less stereospecific outcomes compared to concerted mechanisms. Common examples of elimination reactions include dehydrohalogenation (removal of hydrogen and halogen), dehalogenation (removal of two halogens), dehydration (removal of water), and dehydrogenation (removal of two hydrogen atoms).12