Experiment title: diels-alder reaction. organic technique and overview: synthesis by a cycloaddition reaction involves 1,4-addition of conjugated dienes, in which 2 sigma bonds are formed from two pi bonds. goal of the experiment: synthesize cis-norbornene-5, 6-end-dicarboxylic anhydride from maleicanhydride and cyclopentadiene. experiment protocol: 1). dissolve 0.2g of maleic anhydride in 1.0ml ethyl acetate in a test tube. to this solution, add 1.0ml of hexanes (ligroin). a solvent mixture is used in this reaction because the product is too soluble in 100% ethyl acetate and would not precipitate. 2). add 0.2ml of cyclopentadiene and mix gently with a glass rod. observe the reaction. did the test tube heat up? 3). allow the tube to cool to room temperature, during which crystallization should occur. if it does not, induce it by scratching the inside of the tube with a glass stirring rod. if precipitation still does not occur, cool the solution in an ice bath 4). remove the solvent by vacuum filtration on a hirsch funnel. use a small amount of hexanes to wash the residual crystals from the test tube into the funnel. leave the crystals in the hirsch funnel for a few minutes, with the water still on, to dry them. 5). collect the crystals from the hirsch funnel--if they still seem wet, dry them by pressing them in a folded piece of large filter paper. determine the mass of the product and calculate the percent yield. 6). test the melting point of the final product.