The experiment of Diels-Alder reactions, in particular the furan and maleic anhydride as used in my experiment, observed the exo product as oppose to the exo product. This shows the tendency for the stereochemistry of the Diels-Alder to yield an exo product in preference to the endo product. To determine the stereochemistry, a melt temperature of the product was taken and compared to literature values. The melt temperature for the product was roughly around 113oC, corresponding to the exo Diels-Alder product of furan and maleic anhydride. When compared to the class data of melting ranges, the melting temperature from the reaction was relatively consistent to the majority. Based off this, the assumption can be made that the Diels-Alder prefers …show more content…
The percent yield of products that was calculated for this reaction was about 81.2%, fairly less pure than the previous product but still decently pure. A carbon NMR and H NMR were produced and used to identify the inequivalent carbons and hydrogens of the product. There were 9 constitutionally inequivalent carbons and potentially 4,5, or 6 constitutionally inequivalent hydrogens. On the H NMR there are 5 peaks, but at a closer inspection of the product, it seems there is only 4 constitutionally inequivalent hydrogens because of the symmetry held by the product and of this H’s. However, expansion of the peaks around the aromatic region on the NMR show 3 peaks, which was suppose to be only 2 peaks. In between the peaks is a peak from the solvent, xylene, that was used, which may account to for this discrepancy in the NMR. Furthermore, the product may have not been fully dissolved or was contaminated, leading to distortion (a splitting) of the peaks. The 2 peaks further down the spectrum were distinguished from two H’s, HF and HE, based off of shielding affects. The HF was closer to the O, so it experienced more of an up field shift than HE. On the C NMR, there are 9 constitutionally inequivalent carbons. A CNMR Peak Position for Typical Functional Group table was consulted to assign the carbons to their corresponding peaks. The carbonyl carbon, C1, is the farthest up field, while the carbons on the benzene ring are in the 120-140 ppm region. The sp3 hybridized carbon, C2 and C3, are the lowest on the spectrum. This reaction verifies the statement, ”Measurements have shown that while naphthalene and benzene both are considered especially stable due to their aromaticity, benzene is significantly more stable than naphthalene.” As seen in the reaction, the benzene ring is left untouched and only the naphthalene is involved in the reaction with maleic
Some possible errors raised during the synthesis and spectrometric analysis of TPCP include the insufficient mixing of the hexane and TPCP, in which will result in the low absorbance of the compound. Additionally, the low yield is contributed from the loss of product during filtration.
By comparing the overall percent yields based upon pathway, the statistically superior pathway proved to be the Red pathway, which also happens to be the synthesis pathway I implemented. I determined that this was the best pathway based on the mean, median, and maximum overall percent yields of each pathway and are shown on Table 2. I hypothesize that this pathway was most successful because of the order of the reagents used, specifically that the nitration was the second step. I hypothesize that the addition of the nitro group to the benzoic acid was more successful than other reaction pathways because the attached carboxylic acid group is a moderate deactivator and meta director, more so than the attached ketone in the Blue pathway or the attached ester in the Green
Converting 4-tert-butylcyclohexanol into 4-tert-butylcyclohexanone via oxidation reaction generated 0.270 grams. The product is confirmed through NMR. The second part of the experiment is to convert 4-tert-butylcyclohexanone into 4-tert-butylcyclohexanol via reduction reaction using the product obtained from earlier. However, due to the product having too many impurities, an industrial 4-tert-butylcyclohexanone was used for the experiment. The reaction generated 0.118 grams, a 99.2% yield rate. The NMR confirmed the product to be 4-tert-butylcyclohexanol, with a ratio of 85% trans and 15% cis isomers. In compare to the industrialized alcohol, it has almost the same ratio. Besides L-selectride, trans isomers are more common. The reason as
Fully describes the crystallochemical relationships between the structures and the temperature dependence of polymorphism. )
The tertiary product forms as a result of a hydride shift in order to form a more stable carbocation whereas the secondary (minor) product forms as a result of a direct substitution. The reaction was done via a hot water bath at approximately 55 degrees Celsius in order to overcome some of the activation energy requirements. The analysis of Infrared spectroscopy data showed that there was still a slight amount of alcohol left in the product therefore highlighting that this reaction did not go to completion. This could have been because of an excess of lucas
...Coauthor, ChemBioChem 2006, 7, 1-10; b) A. Author, B. Coauthor, Angew. Chem. 2006, 118, 1-5; Angew. Chem. Int. Ed. 2006, 45, 1-5.))
The 1H NMR spectrum shows that there are 18 protons in 11 different proton environments. This fits with the Diels-Alder reaction taking place a...
As a final point, the unknown secondary alcohol α-methyl-2-naphthalenemethanol had the R-configuration since it reacted the fastest with S-HBTM and much slower with R-HBTM. TLC was a qualitative method and ImageJ served as a quantitative method for determining which reaction was the faster esterification. Finally, 1H NMR assisted in identifying the unknown from a finite list of possible alcohols by labeling the hydrogens to the corresponding peaks.
In this paper, Nicolaou and his associates describe how their goal was both the total synthesis of these CP compounds (achieved in 1999) along with the determination of their absolute configurations; methods used in initial attempts to determine absolute configuration at different carbons included X-ray crystallography and NMR. Nicolaou set about synthesizing this compound by thinking through possible reactions that he might use to begin to build the carbon skeleton needed for this molecule. His team decided on a type-II intramolecular Diels-Alder reaction as the key step to generation of the core skeleton. The Diels-Alder reaction utilizes a dienophile in order to form new carbon-carbon bonds in a single step, in this case to form multiple ring structures. However, Nicolaou ran into trouble when several reagent-based enantioselective approaches with the precursor failed to yield appreciable levels of the desired product. After much study of this problem, Nicolaou's team came to the conclusion that a Lewis acid catalyst would be their best shot at inducing the asymmetry needed for this particular absolute configuration.
Instead, the spectrum for station 2 was examined and compared to an IR spectrum of carvone. In the IR spectrum of carvone, the Peak located at ~1680 cm-1 indicates a carbon oxygen double bond, and the small peaks located just under 3000 cm-1 indicate carbon hydrogen bonds. In the spectrum for the product, the peak the broad Peak ranging from 3300 to 3400 cm-1 indicates an oxygen hydrogen alcohol bond. The peaks just below 3000 cm-1 also indicate hydrogen carbon bonds, and the peak just above 3000 cm-1 indicate vinyl carbon hydrogen bonds. Also the two peaks at around 1600 cm-1 and 1500 cm-1 with the small overtones located at the range of 1800 cm-1 to 2000 cm-1 indicate a benzene ring is present in the product. Based on these peaks, it indicates that the product is carvacrol, and station 2’s experiment was
In this experiment we produced a Nylon-6,10 polymer from a reaction with a sebacoyl chloride (decanedioyl dichloride)/dichloromethane mixture and a mixture of water, 1,6-hexanediamine and sodium carbonate. The name ‘Nylon-6,10’ indicates that the diamine that it was made from has 6 carbons and the diacid it was made from has 10 carbons. The sodium carbonate was used in the preparation of Nylon-6,10 because it is a strong base that will lower the acidity of the solution and neutralize the hydrochloric acid that was produced as a by-product. The HCl was produced as a by-product instead of water because we used milder conditions by substituting decanedioyl dichloride for decanedioic acid. The decanedioyl dichloride is a better alternative because it is more reactive towards the
The purpose of this experiment is to examine the reactivity of different compounds. To accomplish this, different types of benzene (aniline, acetanilide, phenol, or anisole) will be brominated. The reactivity and activation strength will determine of the compound is polyhalogenated, or monohalogenated. In this experiment it is to be predicted in which order the reaction substitution(s) will occur and the reactivity order of each of the benzene compounds. The product will then be analyzed and identified by recrystalling and comparing the melting point of isolated product to literature values.
This shows that our experiment yielded the correct form of each compound. The percent recovery was accurate for 4-Cloroaniline and Naphthalene yielding 99.9 and 109.9 % respectively while Benzoic Acid only yielded 45.95%. Possible reasons for Benzoic Acid yielding such a low percentage might be because of not capping the separator funnel while working to precipitate 4-chloraniline, also not removing all of the Benzoic Acid from the separatory funnel adds to a recovery less than
This suggests that the background scan may not have run properly. However, all of the ferrocene peaks are still clearly visible. The most important peaks in this spectrum are the aromatic ones, which show that the cyclopentadienyl ligand retains its aromaticity on binding to the metal centre. The aromatic C-H peaks occur higher than the C-H stretch in an alkene, and there are also aromatic overtones at 1636 cm-1.
Even though the percent yield was extremely low (19.106%) and the melting point was lower than expected (85-88 degrees C and not 92-94 degrees C), the IR spectrum proved that the final product does not have a carbonyl group, as it was reduced to the alcohol group. The nitro group remain on the IR spectrum, proving that it was not reduced to Aniline. The TLC plate also proves a reduction has occurred, as the product Rf value (0.2195) was lower than the starting material Rf value (0.9512). The primary reason is because the product is the reduced formed of the starting material, resulting in more hydrogens and more hydrogen