CH1012
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ALCOHOLS : SUBSTITUTION
• A characteristic
reaction of alcohols is to
form haloalkanes when treated with HCl, HBr or HI - a nucleophilic substitution.
form haloalkanes when treated with HCl, HBr or HI - a nucleophilic substitution.
•The product forms an insoluble layer above the aqueous
alcohol/acid layer.
eg. CH3CH2OH + HBr ® CH3CH2Br + H2O
Chloride substitution (Lewis acid
catalysed)
3o alcohols
- cHCl, no ZnCl2, 25oC
1o, 2o alcohols - cHCl, ZnCl2, reflux
(boil)
Bromide, Iodide (X = I, Br)
substitution
3o alcohols
- cHX, 25oC
1o, 2o alcohols - cH2SO4 + NaX, reflux (boil)
