Page 90 - Pharm.Org.Chem-I 02-06-05-101
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• Trans alkenes are more stable than cis alkenes.
The cis isomer is less stable due to greater strain from crowding by the
adjacent alkyl groups
H3C CH3 H CH3
HH H3C H
cis-2-Butene trans-2-Butene
Due to Steric effect: less repulsion
More repulsion between 2 CH3 More stable
Less stable
Preparation of Alkenes
Elimination
reactions
- HX - X2 -H2O
(dehydrohalogenation) (dehydration)
(dehalogenation)
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