Dieckmann Condensation Reaction

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Dieckmann Condensation Reaction

• Prepared by
• Maram A. A. Amleh

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Table of Contents

• Cover Slide.
• Table of Content.
• Objectives.
• Background.
• Reaction and Mechanism.
• Applications.
• 8. Conclusion.
• 9. References.

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Objectives

• I prepared this reaction to
• 1.Learn more about dieckmann condensation
  reaction
• 2.Under stand how reaction is occour

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Background

• The Dieckmann Condensation is an intramolecular
  variant of the Claisen Condensation. The reaction
  is most commonly used to prepare 5 or 6 membered
  ring ß-keto esters.
• The formation of 5 membered rings tends to be
  faster than 6 membered rings, although the 6
  membered ring products are generally more
  thermodynamically stable.
• Ring formation becomes progressively more
  difficult to accomplish as the ring size of the
  desired product increases.

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Reaction and Mechanism
6
Application

• The acidic hydrogen between the two carbonyl
  groups is deprotonated in step four. Protonation
  with a Brønsted-Lowry acid (H3O for example)
  re-forms the ß-keto ester. This deprotonation
  step is the driving force for this reaction.
• Owing to the steric stability of five- and
  six-membered ring structures, these will
  preferentially be formed. 1,4- and 1,6 diesters
  will form five-membered cyclic ß-keto esters,
  while 1,5- and 1,7 diesters will form
  six-membered ß-keto esters.

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• The reaction typically employs the sodium
  alkoxide of the alcohol that corresponds to the
  alcoholic moiety of the ester functional groups.
  The reaction can also be promoted by the use of
  one equivalent of sodium hydride and a catalytic
  amount of the corresponding alcohol.

• The Dieckmann Condensation generally cannot be
  used to prepare small, highly strained ring
  systems. Rather than form a three membered ring,
  diethyl succinate undergoes an intermolecular
  Claisen Condensation followed by a Dieckmann
  Condensation to afford the six membered ring
  compound instead of reacting to form the three
  membered ring ß-keto ester as shown following.

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Conclusion

• The base-catalyzed intramolecular condensation of
  a diester. The Dieckmann Condensation works well
  to produce 5- or 6-membered cyclic ß-keto esters,
  and is usually effected with sodium alkoxide in
  alcoholic solvent

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References

• http//www.wikipidida.com.
• http//blog.para-gen.com.
• www.organic-
• chemistry.org/namedreacti...?