Diels Alder Reaction Lab Report
THEORY:
The Diels-Alder cycloaddition reaction was discovered by Otto Diels and Kurt Alder and is very useful in the synthesis of polycyclic compounds. The Diels-Alder reaction can be described as: [4+2] cycloaddition- a diene with 4 π electrons + 2π electrons from the dienophile; a pericyclic concerted reaction- meaning the reaction occurs in a single step (no intermediates) and involves a cyclic redistribution of bonding electrons. In order for a Diels-Alder reaction to take place the diene must be a conjugated system oriented in the s-cis conformation; s-trans dienes can undergo the reaction only if there configuration permits free-rotation around one of the C=C double bonds such that they can assume the s-cis conformation. …show more content…
Diels-Alder reactions are steriospecific (cis-alkenes form cis substituted and trans-alkenes form trans-substituted); this is called syn addition, the configuration of dienophiles is always retained in the product. The diene and dienophile react in such a way that the endo product is formed rather than the exo …show more content…
After refluxing for the allotted time the distillate was poured while hot, to maximize the amount of adduct transferred, into an Erlenmyer flask and allowed to cool to room temperature before placing it an ice bath (We don't Want Broken Glass and Product contaminating our ice bath!). While hot, the solvent keeps the solute dissolved, in a easily transferable liquid state, but loses it solvating ability at cooler temperatures, thus the adduct crystallizes. After its ice bath the solution needs to be suction filtered to separate it from the xylenes (solvent). With the apparatus setup, hose connected and filter paper wet with solvent and aspirator running, the solution can be poured semi-slowly into the buchner funnel. The crystals tend to cling to the bottom and sides of the flask so a spatula will probably be needed to scrape them out. Washing the flask and crystals with ice- cold xylenes completes this process. The resulting dried product was recrystalized using hot ethyl acetate. A hot plate was used to boil ethyl acetate to be poured into a heating beaker with a mixture of EtoAc and adduct until the product dissolved. A sequential suction filtration completed this
The Diels-Alder cycloaddition reaction was discovered by Otto Diels and Kurt Alder and is very useful in the synthesis of polycyclic compounds. The Diels-Alder reaction can be described as: [4+2] cycloaddition- a diene with 4 π electrons + 2π electrons from the dienophile; a pericyclic concerted reaction- meaning the reaction occurs in a single step (no intermediates) and involves a cyclic redistribution of bonding electrons. In order for a Diels-Alder reaction to take place the diene must be a conjugated system oriented in the s-cis conformation; s-trans dienes can undergo the reaction only if there configuration permits free-rotation around one of the C=C double bonds such that they can assume the s-cis conformation. …show more content…
Diels-Alder reactions are steriospecific (cis-alkenes form cis substituted and trans-alkenes form trans-substituted); this is called syn addition, the configuration of dienophiles is always retained in the product. The diene and dienophile react in such a way that the endo product is formed rather than the exo …show more content…
After refluxing for the allotted time the distillate was poured while hot, to maximize the amount of adduct transferred, into an Erlenmyer flask and allowed to cool to room temperature before placing it an ice bath (We don't Want Broken Glass and Product contaminating our ice bath!). While hot, the solvent keeps the solute dissolved, in a easily transferable liquid state, but loses it solvating ability at cooler temperatures, thus the adduct crystallizes. After its ice bath the solution needs to be suction filtered to separate it from the xylenes (solvent). With the apparatus setup, hose connected and filter paper wet with solvent and aspirator running, the solution can be poured semi-slowly into the buchner funnel. The crystals tend to cling to the bottom and sides of the flask so a spatula will probably be needed to scrape them out. Washing the flask and crystals with ice- cold xylenes completes this process. The resulting dried product was recrystalized using hot ethyl acetate. A hot plate was used to boil ethyl acetate to be poured into a heating beaker with a mixture of EtoAc and adduct until the product dissolved. A sequential suction filtration completed this