ABSTRACT
The most prevalent reactions are acid–base reactions, where the presence of a leaving group renders a ß-hydrogen atom acidic, and reaction with a suitable base induces an elimination reaction to form an alkene or an alkyne. This chapter focuses on what are arguably the most important methods, bimolecular and unimolecular elimination from alkyl halides and discusses the syn elimination reaction. The possible reactions are loss of water by removal of a ß-hydrogen to give the alkene directly, ionization to a carbocation by loss of water, or reaction with a nucleophile with direct displacement of water to give the product. The E1 reaction occurs as the major process only when there is no good nucleophile is present. If water were added to this reaction, it would function as a nucleophile making the direct displacement of water process more likely than the E1 reaction.
