Diels-Alder Reaction: Synthesis of cis-Norbornene-5, 6-endo-dicarboxylic anhydride
Diels-Alder Reaction: Synthesis of cis-Norbornene-5, 6-endo-dicarboxylic anhydride
Introduction: The Diels-Alder reaction is a [4+2] cycloaddition of a conjugated diene and a dienophile. This type of reaction was named for Otto Diels and Kurt Alder who were the first to investigate this reaction (Weldegirma, 2012). The Diels- Alder reaction is one of the most important reactions in all of organic chemistry because of the applicability of it. This reaction can form new carbon-carbon bonds and new stereocenters. The Diels-Alder reaction has high synthetic utility for making unsaturated 6-membered rings (Kahn, 2011). The more electron-withdrawing elements there are in the reactants, the faster the reaction will move forward. In the case of cyclopentadiene and maleic anhydride, the reaction takes place quite quickly due to the many electronegative oxygen present in both reactants.
Mechanism:
Side Reaction: Experimental:
Table of Chemicals:
Cyclopentadiene
Maleic Anhydride
Ethyl Acetate
Hexane
66.10 g/mol
98.06 g/mol
88.11 g/mol
86.18 g/mol
MP: -90º C
BP: 39-43º C
MP: 52.8º C
BP: 202º C
MP: -83.6º C
BP: 77.1º C
MP: -96--94º C
BP: 68-69º C
Cyclopenta-1,3-diene
Furan-2,5-diene
Ethyl Acetate
Hexane
Results: The crystals obtained through the Diels-Alder reaction were not plate-like, as were expected. We obtained crystals that were a small and more powdery than plate-like. Even though our crystals did not turn out as we had hoped, the melting point range for our crystals was very close to the literature value.
The calculations for the percent yield are as follows:
First, the moles of the reactants must be calculated:
Through these calculations we can see that the cyclopentadiene is the limiting reagent is the cyclopentadiene because the reaction between cyclopentadiene and maleic anhydride is a 1:1 reaction.
Thus, the maximum amount of
Introduction: The Diels-Alder reaction is a [4+2] cycloaddition of a conjugated diene and a dienophile. This type of reaction was named for Otto Diels and Kurt Alder who were the first to investigate this reaction (Weldegirma, 2012). The Diels- Alder reaction is one of the most important reactions in all of organic chemistry because of the applicability of it. This reaction can form new carbon-carbon bonds and new stereocenters. The Diels-Alder reaction has high synthetic utility for making unsaturated 6-membered rings (Kahn, 2011). The more electron-withdrawing elements there are in the reactants, the faster the reaction will move forward. In the case of cyclopentadiene and maleic anhydride, the reaction takes place quite quickly due to the many electronegative oxygen present in both reactants.
Mechanism:
Side Reaction: Experimental:
Table of Chemicals:
Cyclopentadiene
Maleic Anhydride
Ethyl Acetate
Hexane
66.10 g/mol
98.06 g/mol
88.11 g/mol
86.18 g/mol
MP: -90º C
BP: 39-43º C
MP: 52.8º C
BP: 202º C
MP: -83.6º C
BP: 77.1º C
MP: -96--94º C
BP: 68-69º C
Cyclopenta-1,3-diene
Furan-2,5-diene
Ethyl Acetate
Hexane
Results: The crystals obtained through the Diels-Alder reaction were not plate-like, as were expected. We obtained crystals that were a small and more powdery than plate-like. Even though our crystals did not turn out as we had hoped, the melting point range for our crystals was very close to the literature value.
The calculations for the percent yield are as follows:
First, the moles of the reactants must be calculated:
Through these calculations we can see that the cyclopentadiene is the limiting reagent is the cyclopentadiene because the reaction between cyclopentadiene and maleic anhydride is a 1:1 reaction.
Thus, the maximum amount of
References: 1) Reusch, Rosetta N. "Chemical Reactivity." Chemical Reactivity. Michigan State University, n.d. Web. 14 Sept. 2013. 2) Jaschke, A.; Seeling, B.; Keiper, S.; Stuhlmann, F. Angew. Chem. Int. Ed. 2000, 39, 4576-4579. Enantioselective Ribozyme Catalysis of a Bimolecular Cycloaddition Reaction. 3) Weldegirma, Solomon. "Experiment 2: Diels-Alder Reaction: Synthesis of cis-Norbornene-5, 6-endo-dicarboxylic anhydride." Experimental Organic Chemisty. Fall 2012 ed. Mason: Cengage Learning, 2012. 05 Mar. 2013. Print