Elimination Reaction - Specific Elimination Reactions

Specific Elimination Reactions

The E1cB elimination reaction is a special type of elimination reaction involving carbanions. In an addition-elimination reaction elimination takes place after an initial addition reaction and in the Ei mechanism both substituents leave simultaneously in a syn addition.

In each of these elimination reactions the reactants have specific leaving groups:

  • dehydrohalogenation, leaving group a halide.
  • the dehydration reaction is one where the leaving group is water.
  • the Bamford-Stevens reaction with a tosylhydrazone leaving group assisted by alkoxide
  • the Cope reaction with an amine oxide leaving group
  • the Hofmann elimination with quaternary amine leaving group
  • the Chugaev reaction with a methyl xanthate leaving group
  • the Grieco elimination with a selenoxide leaving group
  • the Shapiro reaction with a tosylhydrazone leaving group assisted by alkyllithium
  • Hydrazone iodination with a hydrazone leaving group assisted by iodine
  • A Grob fragmentation with degree of unsaturation increasing in one of the leaving groups.
  • the Kornblum–DeLaMare rearrangement (elimination over a (H)C-O(OR) bond) with an alcohol leaving group forming a ketone
  • the Takai olefination with two bulky chromium groups.

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