The purpose of this lab is to use the Diels-Alder reaction to combine anthracene and maleic anhydride. Named after its two founders the Diels-Alder reaction is the addition of a conjugated diene (electron rich compound) with a dienophile (electron poor compound). (1) These compounds will be combined using [4+2] cycloaddition, where the numbers 4 and 2 come from the number of π electrons that are used in each compound to synthesize the product. (2) This experiment comes at the cost of losing two π bonds to form two new sigma (σ) bonds in the cyclic compound. (2) Since the driving force of this reaction is the electron rich diene bonding to the electron poor dienophile as seen in Figure1 it is important to realize the effects that an electron withdrawing group would have on each compound. If an electron withdrawing group such as nitro- (NO2) is bonded to the diene it affects the electron density in a way that the diene no longer acts like an electron rich group, voiding the overall reaction as …show more content…
By observing Figure2 (b) the nitro groups are in a cis configuration on the dienophile. This cis configuration is the reason why both the nitro groups in the product appear in the same direction (cis substuents); in the case where the nitro groups are in a trans configuration the groups in the product would be trans substuents. (3) In this experiment anthracene (electron rich) will be bonded with maleic anhydride (electron poor) by using heat to synthesize 9, 10-dihydroanthracene-9,10-α, β-succinic anhydride. The formation of two products is not ideal but luckily easy to separate. In order to separate the major product from the minor product, the addition of cold xylene is used. The minor product and the reactants are soluble in cold xylene, but the major product is insoluble. Washing the product with cold xylene than will result in a rather pure product.
This pushes the carbonyl’s electrons onto the carbonyl carbon, while the Histidine-57 takes one proton from the
For this experiment, stereochemistry was observed by analyzing both the isomerization of dimethyl maleate and carvones. The dimethyl maleate is formed by two methyl ester groups that are connected by an alkene. They are in a cis-conformation meaning they are on the same side of the alkene, therefore the esters are close to one another. This conformation is strained and sterically hindered due to electrons repelling each other and are enantiomers of one another. With the use of radical chemistry, the cis conformation can be changed into a trans configuration where the esters are on opposite sides of one another.
The goal of the experiment is to synthesize a bromohexane compound from 1-hexene and HBr(aq) under reflux conditions and use the silver nitrate and sodium iodide tests to determine if the product is a primary or secondary hydrocarbon. The heterogeneous reaction mixture contains 1-hexene, 48% HBr(aq), and tetrabutylammonium bromide and was heated to under reflux conditions. Heating under reflux means that the reaction mixture is heated at its boiling point so that the reaction can proceed at a faster rate. The attached reflux condenser allows volatile substances to return to the reaction flask so that no material is lost. Since alkenes are immiscible with concentrated HBr, tetrabutylammonium bromide is used as a phase-transfer catalyst.
Abstract In this experiment, the reaction kinetics of the hydrolysis of t-butyl chloride, (CH3)3CCl, was studied. The experiment was to determine the rate constant of the reaction, as well as the effects of solvent composition on the rate of reaction. A 50/50 V/V isopropanol/water solvent mixture was prepared and 1cm3 of (CH3)3CCl was added. At specific instances, aliquots of the reaction mixture were withdrawn and quenched with acetone.
The purpose of this experiment was to learn about the electrophilic aromatic substitution reactions that take place on benzene, and how the presence of substituents in the ring affect the orientation of the incoming electrophile. Using acetanilide, as the starting material, glacial acetic acid, sulfuric acid, and nitric acid were mixed and stirred to produce p-nitroacetanilide. In a 125 mL Erlenmeyer flask, 3.305 g of acetanilide were allowed to mix with 5.0 mL of glacial acetic acid. This mixture was warmed in a hot plate with constantly stirring at a lukewarm temperature so as to avoid excess heating. If this happens, the mixture boils and it would be necessary to start the experiment all over again.
Part A When sodium was added to water, the sodium melted to form a ball that moved around on the surface of water rapidly and hydrogen gas was produced. Because of the amount of heat liberated during this exothermic reaction, the hydrogen gas ignited the sodium with an orange flame while floating on the water. Also, when potassium was put onto the water, the observation was similar to how sodium reacted towards water. The metal was also set on fire, with sparks and a lilac flame. But, in the case of speed of tarnishing between the two elements, potassium was faster than sodium.
Similarly, FAD + 2e- +2H+ is also used to synthesise FADH2 and GTP is formed from GDP + Pi. These energy carrier will enter the electron transport chain to produce
Benzyne Formation and the Diels-Alder Reaction Preparation of 1,2,3,4 Tetraphenylnaphthalene Aubree Edwards Purpose: 1,2,3,4-tetraphenylnaphthalene is prepared by first producing benzyne via the unstable diazonium salt. Then tetraphenylcyclopentadienone and benzyne undergo a diels-alder reaction to create 1,2,3,4-tetraphenylnaphthalene. Reactions: Procedure: The reaction mixture was created. Tetraphenylcyclopentadienone (0.1197g, 0.3113 mmol) a black solid powder, anthranilic acid ( 0.0482g, 0.3516 mmol) a yellowish sand, and 1,2-dimethoxyethane (1.2 ml) was added to a 5-ml conical vial.
Chem 51 LB Experiment 3 Report Scaffold: Bromination of Trans-Cinnamic Acid 1. The goal of this experiment was to perform a halogenation reaction through the addition of two bromides from pyridinium tribromide. This was accomplished by reacting trans-cinnamic acid with pyridinium tribromide. After the reaction took place, melting point analysis was conducted to find out the stereochemistry of the product, which could either be syn-addition, anti-addition, or syn + anti-addition. 2.
In This reaction dimethyl acetylenedicarboxylate was used as the dienophile with a Carbonyl group as the electron-withdrawing group. A resonance stabilized aromatic ring was formed ( favored rection). The nitrobenzene was used to facilitate the by acting as a high boiling solvent, dissolving both reactants, and thereby driving the Diels-Alder reaction. Refluxing moved this reaction further, forming an intermediate. The violet solution turned beige when forming a six-membered ring by losing carbon monoxide.
The purpose of this lab was to provide a more visible representation of reaction kinetics through dye decomposition with differing concentrations of reactants and the addition of ions within the solution. On day one of the lab, a linear relationship between absorbance and concentration of the dye was determined by creating multiple samples of dye with differing concentrations and measuring their absorbance in a spectrophotometer. On lab day two, using a similar method from day one, the absorbance of different reactions was analyzed and the rate order of both the dye and NaOH were determined to be 1 through graphical data analysis. Additional ions were introduced as a part of the experiment and the effect of the addition of KNO3 slowed down
Experiment 2 Report Scaffold (Substitution Reactions, Purification, and Identification) Purpose/Introduction 1. A Sn2 reaction was conducted; this involved benzyl bromide, sodium hydroxide, an unknown compound and ethanol through reflux technique, mel-temp recordings, recrystallization, and analysis of TLC plates. 2. There was one unknown compound in the reaction that was later discovered after a series of techniques described above.
It is understood the mechanism is acid-catalyzed where protons coordinate with the carbonyl oxygen to make the carbonyl carbon more electropositive for nucleophilic attack (Scheme 1). In the experimental procedure all reactants were added together, this is inefficient as the protons can coordinate with either trans-cinnamic acid or methanol. Coordination with methanol is unnecessary as it reduces its nucleophilicity and makes less protons available to coordinate with the carboxylic acid. To improve
There are two methods of obtaining cyclohexane. These two methods are fractional distillation of naphtha and hydrogenation of benzene. Research suggest that the hydrogenation of benzene is the most economical way to create our chemical of choice. According to ICIS, cyclohexane is used in the production of adipic acid used to
The Wittig reaction is valuable reaction. It has unique properties that allows for a carbon=carbon double bond to form from where a C=O double bond used to be located. Creating additional C=C double bonds is valuable due to its use in synthesis. The Wittig reaction will allow the synthesis of Stilbene (E and Z) from a Benzaldehyde (Ketcha, 141).