Pericyclic 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

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.

The Diels-Alder reaction was discovered and named after the Nobel Prize winning scientists Kurt Alder and Otto Diels in 1928. Such a reaction occurs when a diene with two adjacent double bonds is mixed with a dienophile consisting of a double bond in order to create a cyclohexene. The diene must be in the s-cis conformation in order for the electron transfer to engage correctly. If the diene in question is in s-trans conformation then the access to the molecules is limited, thus, no reaction can occur. The dienophile we used was maleic anhydride. Maleic anhydride possesses high electron withdrawing characteristics which caused a very quick reaction. The reaction will

As detailed in Pavia 's Organic Laboratory techniques the reaction is expected to proceed via the following reaction:

After 10 minutes the reaction liquid was separated from the solid using a vacuum filtration system and toluene. The product was stored and dried until week 2 of the experiment. The product was weighed to be 0.31 g. Percent yield was calculated to be 38.75%. IR spectra data was conducted for the two starting materials and of the product. Melting point determination was performed on the product and proton NMR spectrum was given. The IR spectrum revealed peaks at 1720 cm-1, which indicated the presence of a lactone group, and 1730 cm-1, representing a functional group of a carboxylic acid (C=O), and 3300cm-1, indicating the presence of an alcohol group (O-H). All three peaks correspond with the desired product. A second TLC using the same mobile and stationary phase as the first was performed and revealed Rf Values of 0.17 and 0.43for the product. The first value was unique to the product indicating that the Diels-Alder reaction was successful. The other Rf value of 0.43 matched that of maleic anhydride indicating some

Purpose: The purpose of this experiment is to observe a variety of chemical reactions and to identify patterns in the conversion of reactants into products.

1. Purpose: to clarify the mechanism for the cycloaddition reaction between benzonitrile oxide and an alkene, and to test the regiochemistry of the reaction between benzonitrile oxide and styrene.

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.

Aromatic compounds can undergo electrophilic substitution reactions. In these reactions, the aromatic ring acts as a nucleophile (an electron pair donor) and reacts with an electrophilic reagent (an electron pair acceptor) resulting in the replacement of a hydrogen on the aromatic ring with the electrophile. Due to the fact that the conjugated 6π-electron system of the aromatic ring is so stable, the carbocation intermediate loses a proton to sustain the aromatic ring rather than reacting with a nucleophile. Ring substituents strongly influence the rate and position of electrophilic attack. Electron-donating groups on the benzene ring speed up the substitution process by stabilizing the carbocation intermediate. Electron-withdrawing groups, however, slow down the aromatic substitution because formation of the carbocation intermediate is more difficult. The electron-withdrawing group withdraws electron density from a species that is already positively charged making it very electron deficient. Therefore, electron-donating groups are considered to be “activating” and electron-withdrawing groups are “deactivating”. Activating substituents direct incoming groups to either the “ortho” or “para” positions. Deactivating substituents, with the exception of the halogens, direct incoming groups to the “meta” position. The experiment described above was an example of a specific electrophilic aromatic

For this study, each group had the same dienophile, N-methylmaleimide, but different dienes, anthracene-9-methanol or anthracene-9-carboxaldehyde. Initial reaction conducted with anthracene-9-methanol and N-methylmaleimide was successful in generating a generous amount of product; however, due to errors performed during the purification method by recrystallization, some product was lost, thereby resulting in a low yield. Upon completion of the reaction, the Diels-Alder adduct was subjected to analysis by NMR spectroscopy, specifically, Proton NMR. The percent yield of this reaction was expected to be high, however, the reaction yielded a percent yield of 4.88%, which is significantly low. Typically, a low percent yield is an indication of an inefficient reaction; however, in this case, this cannot be concluded due to errors that occurred during the reaction. Theoretically, dienophiles and dienes can have different electron donating and electron withdrawing substituents, thereby changing either can impact the percent yield of the reaction. An electron donating substituents on the diene will increase the percent yield as the chances of the reaction occurring is increased with the increase in the number of electron donating groups. The Reverse is true for dienophiles, as an increase in the number of electron withdrawing groups with lower the energy in the

This paper is about chemical reactions and chemical reaction types. All the data gathered was from conducting multiple experiments. Each experiment was performed carefully and analyzed to obtain the necessary information for the paper. That information included the four signs of a chemical change, the rnx type, and more.

The imide/lactam NH of thymidine, uridine (pKa, 9.38), and guanosine (pKa, 9.42) is weakly acidic and can deprotonate under basic conditions. The resulting nucleophilic anion can react with a variety of reagents such as activated phosphates, dicyclohexylcarbodiimide (DCC), mesitylene sulfonyl chloride, 1-(mesitylene-2-sulfonyl)-3-nitro-1,2,4-triazole (MSNT), acid chlorides, phosphitylating reagents, and electrophilic reagents that are employed during coupling reactions. These side reactions result in nucleobase-derived N- and O-products.

Alkenes are molecules that contain a carbon-carbon double bond and they are hydrated by acid-catalyzed addition of water to that carbon-carbon double bond. This leads to the formation of an alcohol. Two competing processes, hydration and dehydration, establish an equilibrium. The position of the equilibrium is dependent on the condition of the reaction. While hydration of a double bond requires excess water to drive the reaction, dehydration of an alcohol requires the removal of water to complete the reaction. A carbocation is then formed by the addition of a proton to the double bond of norbornene. Steric hindrance determines how the reaction takes place. During such a reaction, the side of the carbocation, formed by the addition

Olefin metathesis refers to a reaction involving rearrangement of alkyl groups attached to alkenes through the consecutive cleavage and formation of carbon-carbon double bonds. The reaction is catalysed by a transition metal complex. The existence of such a reaction was hypothesized nearly

Then, a shift is observed by one of the atoms to the carbocation. And finally, to stabilize the molecule, catalyst is then regenerated to yield the final product.