Diels-Alder Reaction Lab Report

Many sources of error were responsible for recovering a small amount of product. Introduction: The carbon-carbon bond formation is an important tool in organic chemistry to construct the simple as well as an organic compound. There are several

Introduction An unimolecular substitution reaction, SN1 reaction, has a two step mechanism that results in a halide group being displaced by a nucleophile1. In an SN1 reaction, the first step involves the leaving of a halide group to form a carbocation intermediate. This is the rate determining step, and it is also the slowest step. In the second step a nucleophile attacks a face of the the carbocation. Figure 1 displays this mechanism.

The hypothesis was supported by the employed methods. Introduction: This experiment was performed to show how bromination of alkenes reacts, and to be able to successfully synthesize meso-stilbene dibromide. The reaction of bromine with alkenes is an addition reaction where the nucleophilic double bond attacks the electrophilic bromine

Grignard is a reaction that is crucial to forming the new carbon-carbon bond. This is a two-part lab that teaches new techniques; the purpose of this lab is to introduce realistic organic synthesis and apply acid workup to produce triphenylmethanol. A Grignard reaction is characterized by the addition of a magnesium halide (an organomagnesium halide) to an aldehyde or a ketone in order to form a secondary or tertiary alcohol. These reactions are helpful because they serve as a crucial tool in performing important carbon-carbon bond-forming reactions (Arizona State University, 2018). This experiment aimed to observe the mechanisms of a Grignard reply to synthesize triphenylmethanol from benzophenone using phenylmagnesium bromide as the Grignard reagent.

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.

For example, a lone pair from the oxygen in naphtholate anion attacks the carbon that is bonded to bromine from an allyl bromide molecule. This creates a partial C-O bond and a partial broken C-Br bond, then the C-O bond fully bonds

A control was used to compare the reactant and the product, showing a clear appearance that would indicate an alkene being present. Bromine was added to the reactant 4-methylcyclohexanol, and a reddish-brown color appeared, indicating that no reaction took place. Bromine was then added to the product 4-methylcyclohexene, and the clear appearance of the product remained, concluding that an alkene is indeed present. Discussion Given the results obtained post-experiment, the percent yield was calculated to be about 35.5%, which may suggest that either product was lost at some point during the experiment, or side product was formed.

In case of chloramphenicol, the dichloroacetamido group is oxidized to an oxamyl moiety that acylates a lysine residue in the CYP active site; leads to CYPs enzyme inhibition (Juinn et. al., 1998). Quasi-Irreversible

The purpose of this experiment is to perform a two step reductive amination using o-vanillin with p-toluidine to synthesize an imine derivative. In this experiment, 0.386 g of o-vanillin and 0.276 g of p-toluidine were mixed into an Erlenmeyer flask. The o-vanillin turned from a green powder to orange layer as it mixed with p-toludine, which was originally a white solid. Ethanol was added as a solvent for this reaction. Sodium borohydride was added in slow portion as the reducing agent, dissolving the precipitate into a yellowish lime solution.

Therefore, any reaction with a Grignard cannot be used because of this case that the strong nucleophilic carbon of the Grignard causes. Instead, aprotic solvents like THF and diethyl ether are used. Ethers are mostly used because of the oxygen that makes a complex with the Grignard reagent. Water and acid are highly avoided since they are a proton source. Making sure all glassware and tubes are well dried and that water cannot enter the reaction is a very important step.

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.

PALLADIUM-CATALYZED CROSS COUPLING REACTION IN ORGANIC SYNTHESIS The formation of new carbon-carbon bonds is of central importance in organic chemistry and a prerequisite for all life on earth. Through the assembly of carbon atoms into chains, complex molecules, e.g. molecules of life, can be created. The importance of the synthesis of carbon-carbon bonds is reflected by the fact that Nobel Prizes in Chemistry have been given to this area many times: the Grignard reaction (1912), the Diels-Alder reaction (1950), the Wittig reaction (1979), and olefin metathesis to Y. Chauvin, R. H. Grubbs, and R. R. Schrock (2005) and Richard F. Heck , Ei-ichi Negishi, Akira Suzuki (2010) for the development of methods for palladium-catalyzed formation of carbon-carbon

This lab only included double-replacement reaction which allowed for only one of 2 types of products. Products that chemically reacted (solid) or products that didn’t (aqueous). The insoluble products of these double replacement reaction occurred when the cations or anions of the reactant bonded with the cation or anion of the other reaction. When this happens the reactants get paired together with the reactant it bonded with and causes a replacement. This is shown evident in the lab in Station

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

Several protocols were used throughout the extent of the experimentation, such as during the development and purification of the organic complex. In the developmental phase of the organic complex, traditional methods of cycloaddition reactions were studied and analyzed to provide a basic understanding of a possible design for a practical reaction with cyclooctyne, The characteristics of Click Chemistry reactions were also studied and aided the experimental design of this project. The methodology of the experimentation was a slow-addition of cyclooctyne to a refluxing tricarbonyl iron(0) vinylketene complex in distilled hexane and ether. The purpose of this design was to lower the rate of trimerization of cyclooctyne and increase its reactivity