Through an oxidation-reduction reaction sequence, Borneol is converted to isoborneol. First, borneol is oxidized through a reaction with sodium hypochlorite at 400C to form camphor. When the camphor is then reduced by sodium borohydride, isoborneol is formed. The percent yeild of isoborneol collected was 56.4%, and the melting point range was found to be between 174.2-179.90C. Through analysis of the product through 1H NMR spectroscopy the percent purity is found to be 77.2% pure isoborneol. Introduction Oxidation-reduction reactions can be used to stereochemically control and produce many different organic molecules. The oxidation step in this process increases the number of carbon oxygen bonds by losing a hydrogen and breaking that bond. Through the reduction step, carbon-oxygen bond is broken and the hydrogen is returned. In the oxidation of borneol to camphor, a hydrogen is removed from the carbon attached to the hydroxy group. In order for the all the atoms to have octets, the charged carbon forms double bonds with the oxygen atoms. The product produced is camphor. ----------> The camphor then went through reduction with sodium borohydride to make isoborneol. This reaction was able to be stereochemically controlled by limiting the amount of heat we provided. The conversion of camphor to isoborneol has a lower activation energy than what is required to turn camphor into borneol. Though borneol is the more stable product, the energy requirements to form isoborneol are lower because the borohydride is adding to the less sterically hindered point on the carbonyl carbon. The product made is then mostly (85%) isoborneol. More borneol would be expected if more energy was available during the reaction. ... ... middle of paper ... ...his purity calculation doesn't account for the singnal at 2.10ppm corresponding to the acetone in the product. Niether does it account for the signal belonging to CHCl3 at 7.12ppm. This information along with the 33% borneol can be used to account for the low melting point range. The isoborneol produced through this redox reaction was the kinetic product. This kinetic product was less stable, yet it was produced because of the low amount of energy supplied for the reaction. In the formation of isoborneol the hydride ion attacks the carbonyl carbon of camphor on the least hindered site. With more energy the molecules have more effective collisions on the opposite side. With the energy supplied in this reaction, there would be too much steric effect inhibiting the hydride ion from attacking the carbonyl carbon to make the more stable thermodynamic product borneol.
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
The goal of this two week lab was to examine the stereochemistry of the oxidation-reduction interconversion of 4-tert-butylcyclohexanol and 4-tert-butylcyclohexanone. The purpose of first week was to explore the oxidation of an alcohol to a ketone and see how the reduction of the ketone will affect the stereoselectivity. The purpose of first week is to oxidize the alcohol, 4-tert-butylcyclohexanol, to ketone just so that it can be reduced back into the alcohol to see how OH will react. The purpose of second week was to reduce 4-tert-butylcyclohexanol from first week and determine the effect of the product's diastereoselectivity by performing reduction procedures using sodium borohydride The chemicals for this lab are sodium hypochlorite, 4-tert-butylcyclohexanone
2-ethyl-1,3-hexanediol. The molecular weight of this compound is 146.2g/mol. It is converted into 2-ethyl-1-hydroxyhexan-3-one. This compounds molecular weight is 144.2g/mol. This gives a theoretical yield of .63 grams. My actual yield was .42 grams. Therefore, my percent yield was 67%. This was one of my highest yields yet. I felt that this was a good yield because part of this experiment is an equilibrium reaction. Hypochlorite must be used in excess to push the reaction to the right. Also, there were better ways to do this experiment where higher yields could have been produced. For example PCC could have been used. However, because of its toxic properties, its use is restricted. The purpose of this experiment was to determine which of the 3 compounds was formed from the starting material. The third compound was the oxidation of both alcohols. This could not have been my product because of the results of my IR. I had a broad large absorption is the range of 3200 to 3500 wavenumbers. This indicates the presence of an alcohol. If my compound had been fully oxidized then there would be no such alcohol present. Also, because of my IR, I know that my compound was one of the other 2 compounds because of the strong sharp absorption at 1705 wavenumbers. This indicates the presence of a carbonyl. Also, my 2,4-DNP test was positive. Therefore I had to prove which of the two compounds my final product was. The first was the oxidation of the primary alcohol, forming an aldehyde and a secondary alcohol. This could not have been my product because the Tollen’s test. My test was negative indicating no such aldehyde. Also, the textbook states that aldehydes show 2 characteristic absorption’s in the range of 2720-2820 wavenumbers. No such absorption’s were present in my sample. Therefore my final product was the oxidation of the secondary alcohol. My final product had a primary alcohol and a secondary ketone
In a separate beaker, acetone (0.587 mL, 8 mmol) and benzaldehyde (1.63 mL, 16 mmol) were charged with a stir bar and stirred on a magnetic stirrer. The beaker mixture was slowly added to the Erlenmeyer flask and stirred at room temperature for 30 minutes. Every 10 minutes, a small amount of the reaction mixture was spotted on a TLC plate, with an eluent mixture of ethyl acetate (2 mL) and hexanes (8 mL), to monitor the decrease in benzaldehyde via a UV light. When the reaction was complete, it was chilled in an ice bath until the product precipitated, which was then vacuum filtrated. The filter cake was washed with ice-cold 95% ethanol (2 x 10 mL) and 4% acetic acid in 95% ethanol (10 mL). The solid was fluffed and vacuum filtrated for about 15 minutes. The 0.688 g (2.9 mmol, 36.8%, 111.3-112.8 °C) product was analyzed via FTIR and 1H NMR spectroscopies, and the melting point was obtained via
The experimental Fischer esterification of 8.92g of acetic acid with 5.0g of isopentyl alcohol using concentrated sulfuric acid as a catalyst yielded 4.83g (65.3% yield) of isopentyl acetate. The product being isopentyl acetate was confirmed when the boiling point during distillation had similar characteristics to that of the literature boiling points2. Physical characteristics like color and smell also concluded a match of our product with what was intended. 1H-NMR spectroscopy analysis supported this claim due to the fact that the integration values and chemical shifts were comparable to isopentyl acetate. Lastly, infrared spectroscopy (IR) showed similar key characteristics of our product’s wavelengths to that of pure isopentyl acetate5.
The theoretical weight was 599.6 mg. This yields a percent yield of 3.7%. Table 1 also illustrates the experimental melting point of 99.3-102.1◦C. A melting point that has a range larger than 3◦C is indicative of impurities in the sample. A few possibilities of impurities could have been unreacted norbornene, and water. Evidence that supports that there was unreacted norbornene in the final sample was the fact that the product was a jelly-like structure. Norbornene by itself has a jelly-like structure. However, once norbornene reacted with the acid-catalyst (H2O2), then it should have changed the chemical structure of the molecule and once the solution was brought back down to room temperature, crystals should have formed. Since a jelly-like, or oil-like product was present at the end of the reaction, then this is indicative that there was unreacted norbornene in the sample. The second impurity that may have been present in the final product was water. Instead of adding 3 mL of sodium bicarbonate and then 3 mL of brine, 3 mL of brine was added first and then 3 mL of sodium bicarbonate was added. This experimental error caused excess aqueous solution to be added to the diethyl ether. Since excess water was added to the final product, about 4x the amount of anhydrous sodium sulfate was needed in order to remove the water from the product. This was another indication that there was too much water in
This experiment was divided into two main steps. The first step was the addition of bromine to trans-stilbene. Trans-stilbene was weighted out 2.00g, 0.0111mol and mixed with 40ml of glacial acetic acid in 100ml Erlenmeyer flask on a hot bath. Pyridinium hydrobromide perbromide of 4.00g, 0.0125mol was added carefully into the flask.
...teraction of the HOMO of the diene and the LUMO of the dienophile. This reaction was done at relatively low temperatures as the dry ether has a boiling point of 34.6 °C. At low temperature the endo preference predominates unless there is extreme steric hindrance, which in this case there is not. The endo product forms almost exclusively because of the activation barrier for endo being much lower than for exo. This means that the endo form is formed faster. When reactions proceed via the endo for the reaction is under kinetic control. Under kinetic control the adduct is more sterically congested, thus thermodynamically less stable. The endo form has a lower activation energy, however, the EXO form has a more stable product. As this is a symmetrical Diels-Alder reaction there is not two possible isomers of the product.
Reacting 1-butanol produced 2-trans-butene as the major product. 1-butanol produces three different products instead of the predicted one because of carbocation rearrangement. Because of the presence of a strong acid this reaction will undergo E1 Saytzeff, which produces the more substituted
yield of the pure product was determined to be 95.42%. PURPOSE The purpose of this lab was to perform an electro-philic aromatic substitution and determine the identity of the major product. TLC was used to detect unreacted starting material or isomeric products present in the reaction mixture. RESULTS The theoretical yield of the m-nitrobenzoate was determined to be 4.59 grams.
In a small reaction tube, the tetraphenylcyclopentadienone (0.110 g, 0.28 mmol) was added into the dimethyl acetylene dicarboxylate (0.1 mL) and nitrobenzene (1 mL) along with a boiling stick. The color of the mixed solution was purple. The solution was then heated to reflux until it turned into a tan color. After the color change has occurred, ethanol (3 mL) was stirred into the small reaction tube. After that, the small reaction tube was placed in an ice bath until the solid was formed at the bottom of the tube. Then, the solution with the precipitate was filtered through vacuum filtration and washed with ethanol. The precipitate then was dried and weighed. The final product was dimethyl tertraphenylpthalate (0.086 g, 0.172mmol, 61.42%).
The isomerization procedure was done in order to create dimethyl fumarate from dimethyl maleate. Dimethyl maleate and dimethyl fumarate are cis and trans isomers, respectively. This procedure was done via a free radical mechanism using bromine. The analysis of carvones reaction was done in order to identify the smell and optical rotation of the carvone samples that were provided. The odor was determined by smelling the compound and the optical rotation was determined using a polarimeter.
Benzyl bromide, an unknown nucleophile and sodium hydroxide was synthesized to form a benzyl ether product. This product was purified and analyzed to find the unknown in the compound. A condenser and heat reflux was used to prevent reagents from escaping. Then the solid product was vacuum filtered.
oxaloacetate in the presence of carbon dioxide by phosphoenolpyruvate carboxylase. Oxaloacetate is then hydrogenated by malate dehydrogenase and NADH to malate and NAD+. The enzyme fumarase turns malate into fumarate
The hydroxyl radical is the most important reactive species responsible for the destruction of the organic pollutant.