Diels-Alder Synthesis of 4-Cyclohexene-Cis- 1,2-Dicarboxylic Anhydride from Butadiene Sulfone and Maleic Anhydride.

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Synthesis of the Diels-Alder Adduct Purpose: To investigate the methods behind Diels-Alder chemistry through the synthesis of 4-cyclohexene-cis- 1,2-dicarboxylic anhydride from butadiene sulfone and maleic anhydride. By using a hands-on approach through laboratory synthesis, I hope to gain a better understanding of the concepts governing Diels-Alder reactions. Theory: The Diels-Alder reaction is a cycloaddition reaction that occurs between a conjugated diene, a molecule with two alternating double bonds, and dienophile, an alkene, to form rings and bicyclic compounds. Because it involves the interaction of four π electrons that are supplied by the diene and the two π electrons supplied by the dienophile, the Diels-Alder reaction is often called [4 + 2] cycloaddition. In the reaction, two new σ bonds are formed and one π bond is formed at the expense of two π bonds, which results in a cyclic product. Diels-Alder reactions are pericyclic reactions, which are ones that take place in a single step, without intermediates, and that involve the flow or redistribution of bonding electrons. The reaction proceeds through a cyclic transition state and is concerted, meaning bonds in the transition state are simultaneously made or broken. The Diels-Alder reaction is facilitated when the dienophile is the substituted with electron-withdrawing groups such as nitriles, amines, and carbonyls and when it reacts with dienes that contain electron-donating groups like alkyls and alkoxys groups. Diel’s Alder reactions have unique characteristics and requirements. First, they are stereospecific, meaning cis-alkenes form cis-substituted products and trans-alkenes form trans-substituted products. The diene undergoes syn addition to the dienophile, and two new carbon-carbon sigma bonds are formed on the same face of the diene or dienophile. Because Diels-Alder reactions are

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