An elimination ration involves the loss of two atoms or groups from the substrate, resulting in a formation of a pi bond. Elimination may be first-order (E1) or second-order (E2). E1 is a unimolecular because the rate-determining transition state involves one molecule instead of a collision between two molecules, which is seen in E2. In the presence of a strong acid, alcohols protonate to form a good leaving, for example, water. After the loss of a proton next to the good leaving group, unsaturation occurs resulting in a double bond. There are several promoting factors involved in these two reactions, favoring one process over another. E1 reaction usually involves a weak base, while in E2 a strong base is required. E1 also requires a good ionizing solvent. A substrate also has effects on the reactions: for both E1 and E2, the order of reactivity is tertiary>secondary>primary. (Wade 2006) One example of a reaction that will favor E1 would be the reaction of t-butyl bromide in ethanol......
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