Reaction Between Diene And Diele

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

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

The triple bonds of the alkynes are subject to electrophilic additions reactions. Electrophilic reagents, or Lewis acids, can easily react with the pi-electrons of the triple bond, which act as a Lewis base. An equivalent amount of a halogen or hydrogen halide can be added to produce a double bond and a second equivalent amount can be added to create a saturated product.

The partial positive bromine atom is added to the alkene yielding a bromonium ion intermediate that stabilizes the compound. In the second step, the negatively charged bromide ion behaves like a nucleophile to attack the bromonium ion to open the three-membered ring and add the second bromine. This reaction is an anti-addition reaction because of the steric hindrance caused by the bromonium ion, and therefore two chiral centers are generated with opposite configurations based on the Cahn-Ingold-Prelog nomenclature system. Dehalogenation is a double electrophilic elimination reaction which is the reverse of halogenation. A strong base such as potassium hydroxide to remove a hydrogen and a bromine in an antiperiplanar fashion twice to yield an alkyne.

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 goals in this lab were to have a reaction occur with 4-methylcyclohexanol and an acid catalyst to form our product of 4-methylcyclohexene via an E1 reaction. This reaction is accomplished by removing the –OH group on 4-methylcyclohexanol via dehydration and to have a double bond form via a loss of a hydrogen on a β-Carbon.

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

Within this experiment a type of cycloaddition reaction was performed, called Diels-Alder reaction. This type of reaction involves both a 1,3-diene and an alkene, called the dienophile in this reaction. Within this reaction two new sigma bonds were formed at the 1 and 4 carbon atoms of the diene. Two other pi bonds are also formed simultaneously with the sigma bonds. Due to this concerted nature of the reaction the diene must be able to adopt a s-cis configuration, making the reaction stereospecific.

The reaction was refluxed under nitrogen gas for overnight and completion was checked by the TLC (Ethylacetate: hexane; 2:3). The reaction mass was cooled to RT. Then the solvent was completely evaporated under reduced pressure. Obtained a black colored product. It was purified by silica column chromatography (10:90 ethyl acetate: hexane) to get the compound (3a-d)

Maleic anhydride underwent the Dials-Alder reaction with distilled cyclopentadiene as the dienophile. The reaction was a cycloaddition which produced cis-Norbornene-5,6-endo-dicarboxylic Anhydride surface. (1) Product one had a mass of 9.351 grams and product two had a mass of 9.572 grams. The theoretical yield was found to be 10.047 grams, which makes the percent yield to be 93.07%. Melting Points were found to confirm the purity of the product. Product one had a melting point of 163.7-164.8°C. Product two had a melting point of 162.2-163.9°C.

The purpose of this experiment is to convert carbonyl compounds to alkenes using Wittig reaction. In this case we will be synthesizing Trans-9-(2-phenylethenyl) anthracene from benzyltriphenylphosphonium chloride and 9-anthraldehyde. We will also aim to obtaining a high percent yield and purity for the synthesis of Trans-9-(2-phenylethenyl) anthracene. The mechanism for this reaction goes thus:

One of the most important things organic chemists do is synthesize new and complex structures from simpler structures by chemical reactions. The techniques done in

Two different reactions had been performed and formed the cis and trans products. Isomers that are cis are defined as molecules that have higher priority groups both on same sides of a molecule. Molecules that have higher priority groups both on opposing sides are trans isomers. The compound 1,2-cyclohexanediol is formed using methydioxirane. This is a compound prepared using acetone as well as oxone.

5,5-dimethyl-1,3-cyclohexanedione, or "dimedone" will be prepared using diethyl malonate and distilled mesityl oxide via carbonyl reactions such as Michaels addition and Claisen condensation reactions (Scheme 1).1 Also, the dimedone 13 exists in two forms: keto and enol forms. The form of dimedone will be influenced by the fast equilibrium between the dimedone and the solvent.2 As seen in the dimedone spectra in different concentration of solvent ( spectrum ), the keto-enol forms can be distinguished by comparing their the keto and enol CH3 peaks in the spectra. In addition, the derivatives of dimedone 19, hexahydroacridinedione, will be synthesized from the purified dimedone 13 and p-isopropylbenzaldehyde 14 and ammonium acetate in Scheme 2.

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