1. Preparation of Alkenes

2. - these are elimination reactions
- follow Saytzeff’s Rule – when a molecule of the form “HX” is eliminated from a compound, the hydrogen is removed from the adjacent carbon containing the least number of hydrogens, thus forming the more highly substituted product

3. 1. Dehydration of alcohols - elimination of H-OH in the presence of a strong acid (usually H2SO4) and heat
Ex. 1. Dehydrate ethanol
Ex. 2. Dehydrate 2-butanol

4. 2. Dehydrohalogenation - eliminationof HCl or HBr
Utilizes KOH and ethanol (ethyl alcohol, C2H5OH, ETOH) as reagents
Ex. 1. Dehydrohalogenate chloroethane.
Ex. 2. Dehydrohalogenate 2-bromobutane.