Diels Alder Reaction Lab Report

Introduction
The experiments in this lab each involved a Diels-Alder reaction. A Diels-Alder reaction is a one-step reaction between a conjugated diene and a dienophile. The Diels-Alder reaction is exothermic. In the reaction, the bonding electrons rotate to form carbon-carbon bonds which then create a cyclohexane ring product. The product can be exo or endo. The endo product is the major product since they are the more favored kinetically. In order for a Diels-Alder reaction to occur, the diene must be in the s-cis conformation. If a diene is unable to change from s-trans, which is when it’s most stable, the Diels-Alder reaction cannot happen.
The Diels-Alder reaction is named after a German professor by the name of Otto Diels and his student

Tetraphenylcyclopentadienone (0.100 g, 0.260 mmol), dimethyl acetylenedicarboxylate (0.1 mL), and nitrobenzene (1 mL) were placed in a small reaction tube along with a boiling stick. The reaction tube was heated to a reflux using a sand bath until the purple soln. turned a tan color. When the soln. was warm to touch, ethanol (3 mL) was stirred in. Next the reaction tube was placed in ice. The material was collected using vacuum filtration. The resulting solid was washed with ethanol and the color was white. Once the product was dried completely, the weight was taken (0.078 g, 0.235 mmol,

Tetraphenylcyclopentadienone (0.100 g, 0.260 mmol) and diphenylacetylene (0.500 g, 2.805 mmol) were added to a small reaction tube. A cap was placed on the reaction tube, but not tightened. A sand bath heated the mixture to a reflux until the color became brown. Once the soln. cooled to room temperature, the tube was shaken gently until a white solid formed on the bottom. Diphenyl ether (2 mL) was added to the reaction tube and the reaction tube was heated again until all of the solid dissolved. Then the reaction tube was cooled to room temperature and toluene (2 mL) was added to the tube and placed in an ice bath. Finally the product was collected using vacuum filtration and washed with toluene. The light brown product was dried and weighed (0.088 g, 0.165 mmol,