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Bimolecular Elimination Reaction (E2)
You have to
determine E or
Z alkene
Properties of E2:
1. Single-step (concerted).
2. Stereospecific.
3. Reaction rate = k [RX][Base].
Factors affecting E2
1. Requires strong bases: alc. KOH , RO- , NaNH2.
2. Polar aprotic solvent: DMF, DMSO, acetone.
E2 orientation
α
ββ
Saytzeff rule: ‘In dehydrohalogenation the prefered
product is the alkene that has the greater number of alkyl
groups attached to the doubly bonded carbon atoms’
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