12. E2 Reaction of alcohols

E2 Reaction of alcohols

Alcohols gives E2 reaction with Al₂O_3, P₂O₅, ThO₂, WO₃

• With Al₂O₃ and P₂O₅ Saytzeff alkene is major product but with ThO₂ and WO₃ Hofmann alkene is major product.

Pinacol-Pinacolone rearrangement :

Mechanism :

Note : For unsymmetrical diol that –OH group will be replaced first which will generate stable carbocation as below .

Ex.