4.141-Butanol is a primary alcohol; 2-butanol is a secondary alcohol. A carbocation intermediate ispossible in the reaction of 2-butanol with hydrogen bromide but not in the corresponding reaction of1-butanol.The mechanism of the reaction of 1-butanol with hydrogen bromide proceeds by displacement ofwater by bromide ion from the protonated form of the alcohol (the alkyloxonium ion).Protonation of the alcohol:Displacement of water by bromide:The slow step, displacement of water by bromide from the oxonium ion, is bimolecular. The reactionof 1-butanol with hydrogen bromide follows the SN2 mechanism.The reaction of 2-butanol with hydrogen bromide involves a carbocation intermediate.Protonation of the alcohol:Dissociation of the oxonium ion:Capture of sec-butyl cation by bromide:The slow step, dissociation of the oxonium ion, is unimolecular. The reaction of 2-butanol with
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This note was uploaded on 09/20/2011 for the course CHM 2210 taught by Professor Reynolds during the Spring '01 term at University of Florida.