Diels-Alder Reaction Lab

The product was then suspended in 2 ml of water with a stir rod in a 50 ml Erlenmeyer flask and heated to boiling. Water was added in one milliliter increments until all the product was dissolved (18 ml added total). The saturated solution was allowed to slowly cool, and gradual white crystal formation was observed. Recrystallized product was collected once more by suction filtration with the Hirsch funnel once crystallization ceased. Collected product dried on a watch glass for a week, weighed 0.14 g (1.2 mmol), and the melting point was 139°-141°

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.

Sodium hydrosulfite (254 mg, 1.46 mmol, 2.00 eq.) was added. The walls of the conical vial were then washed down with (1 mL, 55.6 mmol, 1.00 eq.) and the solution was refluxed for 5 minutes using the aluminum block, hot plate, and a jacketed condenser with water in/out attached and water flowing throughout the system.1 The solution was cooled to room temperature and then acetic acid (1mL, 17.49 mmol, 1eq.) was added and stirred for 5 minutes.1 The solution was then cooled on ice for 10 minutes, which caused it to thicken significantly. The resulting product was then obtained by vacuum filtration for 5-10 minutes, until the product was thoroughly dried.1 The solid precipitate obtained was luminol (133 mg, .6421

The product appeared to be as desired, a visibly green dye. The second reaction was prepared by synthesis of the reagent, benzoic acid. This reagent was prepared from phenylmagnesium bromide and carbon dioxide in anhydrous THF. this is shown in Scheme 2 below.

The Grignard Reaction Huzaifa Amjad, Maitlyn Mullen, Sebastian Eady Introduction: A Grignard reagent is an extremely reactive chemical compound used in the synthesis of hydrocarbons, alcohols, carboxylic acids, and other compounds (1). Grignard reagents have a formula of RMgX, where R is an alkyl or aryl group and X is a halogen. The balanced equation is shown below in Equation 1. 2RMgX  R2Mg + MgX2 Eq.

Results Synthesis. The synthesis of cyclohexene by dehydrating cyclohexanol through distillation had a crude yield of approximately 75%, the overall yield being 56% after extraction. Infrared Spectroscopy (IR) and Gas Chromatography/Mass Spectrometry (GC/MS) results indicate the presence of cyclohexanol in the product; therefore, the reaction did not go to completion. However, the spectra do display peaks characteristic and expected for cyclohexene, suggesting that the intended material was indeed synthesized but possibly in low concentrations.

Due to that reason, the reaction has a good control over the regiochemical and stereochemical properties of the newly formed six-membered compounds. Therefore, this reaction is a reliable technique in the synthetic organic chemistry field. The Diels-Alder reaction is a nucleophilic and electrophilic reaction as the

After production of product 11 hydrogenation of this product can be preformed in H2O with tartaric acid to produce 12. Then the hydroxyl group in 12 can be protected as an ethyl carbonate to produce 13. After this a Grignard addition is used to produce either 16 or 17, with 6 equivalents of Grignard reagent or 10 equivalents (12). Both 16 and 17 can then be pushed towards buprenorphine by treatment with NaOH in methanol/dichloromethane. The best yield pathways are the 11, 12, and 13 pathways with 11 and 12 being easier to conduct, because of the crystalline intermediates

Due to time constraints, we weren't able to get as much done as originally intended. Several reactions had to be completed multiple times and still had varying results. By the end, most of our products were not completely isolated but we did have evidence of some product formed for each. This lab gave us the opportunity to see reactions such as the Grignard reaction, bromination of a C=C bond, and the saponification of an ester. Additionally, we learned about the reactivity of acid chlorides and difficulties associated with them.

A white powderish anthracene and white somewhat-crystallized maleic acid were used as starting product to yield 9, 10-dihydroanthracene-9, 10-succinic anhydride via diels-alder mechanism. A very simple and easy reflux technique was used to run the reaction followed by recrystallization. There was

Indicate which of the following pairs of reagents will participate in a classical Diels-Alder reaction.

With the presence of carboxylic acid (which is active in the reaction of the synthesis) in the results done by an electronic instrument, it shows that the reaction went through the right direction.

The reacting itself is energetically favorable, as the newly synthesized sigma bonds are more stable than the previously broken pi bonds.2,3 For a Diels-Alder reaction to occur or be favored, high heat and high pressure conditions must be applied to a reaction, and in some cases catalyst consisting of Lewis acids are used.2 However, to further favor the occurrence of a Diels-Alder reaction, dienophiles must contain electron withdrawing substituents and dienes must contain electron donating

Carbon-Carbon bonding reactions in chemistry are important because they allow the diversity and generation of larger molecules. Aldol additions and Grignard reactions are few of many well understood methods for generating carbon-bonds bonds.1 The products of aldol additions are formed from ketone and aldehyde groups under acid or basic conditions. Catalyzed by these conditions the ketones undergo tautomerization between keto-enol forms, the enolate reacting with a neighboring aldehyde. The new bond is created between the alpha carbon of ketone and electrophilic center of the aldehyde by electrophilic 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