Diels-Alder Reaction Lab Report

Diels-Alder Reaction Objective: The objective of this experiment is to demonstrate a typical Diels-Alder reaction by reacting anthracene (diene) with maleic anhydride (dienophile) to produce 9,10-dihydroanthracene-9,10-α,β-succinc acid anhydride, the product. Scheme 1. Cycloaddition through the Diels-Alder Reaction1 Experimental: Anthracene (1.00 g, 5.61 x 10-3 mol), maleic anhydride, (0.75 g, 7.65 x 10-3 mol), and xylene (5.0 mL) were combined in a 10 mL long-necked, round-bottomed flask. A stir bar was added and an empty distillation column was attached to the flask to function as an air condenser. The mixture was refluxed for 40 minutes over a sand bath, ensuring the temperature was monitored to prevent the reflux ring from surpassing the

Discussion: In the synthesis of 1-bromobutane alcohol is a poor leaving group; this problem is fixed by converting the OH group into H2O, which is a better leaving group. Depending on the structure of the alcohol it may undergo SN1 or SN2. Primary alky halides undergo SN2 reactions. 1- bromobutane is a primary alkyl halide, and may be synthesized by the acid-mediated reaction of a 1-butonaol with a bromide ion as a nucleophile. The proposed mechanism involves the initial formation of HBr in situ, the protonation of the alcohol by HBr, and the nucleophilic displacement by Br- to give the 1-bromobutane. In the reaction once the salts are dissolved and the mixture is gently heated with a reflux a noticeable reaction occurs with the development of two layers. When the distillation was clear the head temperature was around 115oC because the increased boiling point is caused by co-distillation of sulfuric acid and hydrobromic acid with water. When transferring allof the crude 1-bromobutane without the drying agent,

Part 1: Esters aromas are very distinct and often pleasant, they are often used in food aroma and fragrances.1 Esters chemical properties are distinguished by their low molecular weight and low boiling points, caused by their dipole-dipole and dispersion interaction.2 Esters are the result of a condensation reaction, in which a carboxylic acid, an alcohol, and an acid catalyst react to create a water molecule and an ester.

For this experiment, an organometallic reagent was used for the synthesis and isolation of benzoic acid. The Grignard reaction is the addition reaction of an organometallic reagent, which in this case was an organomagnesium reagent. An organometallic reagent is a carbon bonded to a metal. This reagent was combined with an electrophile, a carbonyl compound such as a ketone or aldehyde. Carbons are electrophilic when bound to a nonmetal thus the atoms are more electronegative than the carbon and metals are less electronegative than carbon.

We used TLC analysis to identify each product obtained from the dihydroxylation reactions by spotting a TLC plate with the product of our reaction, a solution of cis-cyclohexane, trans-cyclohexane, and a 50:50 mixture of the two. We then placed the plate in a beaker with ethyl acetate saturating the atmosphere to allow the TLC plate to develop. Finally, we compared Rf values of the components of the mobile phase, after the phase was completed. 100% ethyl acetate was used instead of 100% Hexane or a mixture of Ethyl Acetate, because ethyl acetate has high polarity and can separate the components of a mixture to elution, unlike hexane, which is non-polar, and therefore unable to separate the components of the mixture. A 50:50 mixture of both would not work, because the polar and non-polar compounds would neutralize the mixture, and thereby not separate the components of the mixture.

The hypothesis tested in this experiment was, if the temperature of enzyme catalysis were increased, then the reaction rate would increase, because enzyme-catalysis reacts by randomly colliding with substrate molecules, and the increase in temperature increases the speed of collision or reaction rate. The final data collected for the experiment was positive with my hypothesis. The coffee filter, covered in potato solution, sank and rose at a faster pace in the hydrogen peroxide when the temperatures were raised.

In this experiment, meso-stilbene dibromide was used to produce diphenylacetylene through two sequential dehydrohalogenations. The first part is a concerted E2 mechanism, where the reactant is deprotonated at the beta carbon from the halide ion that will be leaving. This creates a transition state where the leaving hydrogen and halide are anti-periplanar with each other, meaning that they are at a 180° angle in relation to one another. This reaction is caused by a base—in this case, potassium hydroxide—and produces a haloalkene, or vinyl halide. Potassium hydroxide was only added to reaction when needed, as

A Diels-Alder reaction involves a cyclic flow of electrons in a concerted step in which the conjugated diene, supplies 4 pi electrons and the alkene or alkyne, known as the dienophile, supplies 2 pi electrons. In this process, two new sigma bonds, which link the former dienophile to the diene, and one new pi bond, between the former double bonds on the diene, are formed. Furthermore, the reaction can involve molecules with a large variety of substituents, as long as there is a diene with electron donating groups and a dienophile with electron withdrawing groups as this can speed up the reaction. A critical part of the

The oxidation number of an atom of any free element is ZERO. Means to say there is only one kind of atom present, no charge.

For this lab, certain actions were performed to facilitate the optimal conditions for the Grignard reaction to proceed. As mentioned above, forming the Grignard reagent and the Grignard reaction must take place in dry, anhydrous conditions. This was why the glassware was initially placed in the oven to evaporate any moisture that was present on the glassware. Additionally, the magnesium used in the experiment needed to be dry too, so it was also placed in the oven to be heated. Creating a dry environment was also why the reaction vessel was covered in the septum because it helped prevent the moisture in the air from entering the reaction. Having water in the reaction vessel would destroy the Grignard reagent and hinder the Grignard reaction. Because the reaction needed to be done in dry and anhydrous conditions, diethyl ether was used as the solvent because it was aprotic meaning that the formation of phenylmagnesium bromide and the Grignard reaction would not be hindered by the protonation of water and alcohols3.

Ans. Chair conformer of cyclohexane has negligible dipole moment due to symmetry and equal charge distribution. On the other hand Boat conformation of cyclohexane has dipole moment due to the shape of the conformer making it polar due to charge distribution and steric effects.

The purpose of this experiment is to examine the reactivities of various alkyl halides under both SN2 and SN1 reaction conditions. The alkyl halides will be examined based on the substrate types and solvent the reaction takes place in.

Through the use of the Grignard reaction, a carbon-carbon bond was formed, thereby resulting in the formation of triphenylmethanol from phenyl magnesium bromide and benzophenone. A recrystallization was performed to purify the Grignard product by dissolving the product in methanol. From here, a melting point range of 147.0 °C to 150.8 °C was obtained. The purified product yielded an IR spectrum with major peaks of 3471.82 cm-1, 3060.90 cm-1, 1597.38 cm-1, and 1489.64 cm-1, which helped to testify whether the identity of the product matched the expected triphenylmethanol. The identity of the product being correct was further confirmed by way of both proton and carbon-13 NMR spectra. This is due to the fact

Dispense .5 mL water into the already weighed conical vial, replace cap and face insert on its down side.

The objective of this experiment is to successfully perform a dehydration of 1-butanol and 2-butanol, also dehydrobromination of 1-bromobutane and 2-bromobutane to form the alkene products 1-butene, trans-2-butene, and cis-2-butene. The dehydration reactions react under and acid-catalysis which follows an E1 mechanism. It was found that dehydration of 1-butanol yielded 3.84% cis-2-butene, 81.83% trans-2-butene, and 14.33% 1-butene, while 2-butanol is unknown due to mechanical issues with the GC machine. For the dehydrobromination, with the addition of a