Diel-Alder Reaction Lab

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

Theory: One of the methods of preparing alkyl halides is via the nucleophilic substitution reactions of alcohols. Alcohols are inexpensive materials and easy to maintain. However, they are a poor leaving group the OH group is a problem in nucleophilic substitution, this problem is fixed by converting the alcohol into H2O.

A chemical reaction is when substances (reactants) change into other substances (products). The five general types of chemical reactions are synthesis (also known as direct combination), decomposition, single replacement (also known as single displacement), double replacement (also known as double displacement), and combustion. In this lab, the five general types of chemical reactions were conducted and observations were taken before, during, and after the reaction. Then the reactants and observations were used to determine the products to form a balanced chemical equation. The purpose of this lab was to learn and answer the question: How can observations be used to determine the identity of substances produced in a chemical reaction?

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

The reaction involves a nucleophilic acyl substitution on an aldehyde, with the leaving group concurrently attacking another aldehyde in the second step. First the Potassium hydroxide attacks a carbonyl, which forms a tetahedral intermediate which then collapses when attacked by another hydroxide. The carbonyl is formed again when its hydride attacks another carbonyl. In the final step of the reaction, the acid and alkoxide ions formed exchange a proton. In the presence of a very high concentration of base, the aldehyde first forms a doubly charged anion from which a hydride ion is transferred to the second molecule of aldehyde to form carboxylate and alkoxide ions. Subsequently, the alkoxide ion acquires a proton from the solvent.

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

Abstract: Using hypochlorous acid to convert secondary alcohol called cyclododecanol to the corresponding ketone which is cyclododecanone by oxidation.

These triple bonds are created by overlapping two pairs of p-orbitals that create a right angle on adjacent sp-hybridized carbon atoms. Two successive elimination reactions are used to prepare alkynes in a manner like the creation of double bonds. The first elimination reaction produces a double bond and the second creates the triple bond. These reactions are done using a strong base and heat.

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.

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.

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.

Polymers are formed through a process of polymerisation reactions (10), the most common reaction types being addition and condensation reactions (10). In an addition polymerisation reaction (Figure 1), double-bonded hydrocarbons (alkenes) react together to break their double bonds and covalently bond to form monomers (10). Highly branched molecules have the inability to 'line up' with one another which causes an amorphous solid, which does not have a predictable arrangement or repeating pattern (10). Long-chain molecules have regular and repeating structure which causes cyrstallinity, due to the increased attraction of intermolecular forces (10). Condensation reactions occur when a hydrocarbon molecule also contains oxygen, where two functional groups containing hydrogen are present on each molecule (10). These molecules form a dimer when attached together which then combine to create a polymer, and results in a water product

Single Mechanism that leads to Mixture of both Syn and Anti Mechanism: Both frontside and backside attack occurs but the most predominant product is the one that is most stable. Most stable would be anti structure.

Combustion Reaction – it is a reaction where oxygen is the common reactant . It happens when oxygen and a compound reacts with each other. It produces heat and a new product .

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.