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.
Alcohol, which is the nucleophile, attacks the acid, H2SO4, which is the catalyst, forming oxonium. However, the oxonium leaves due to the positive charge on oxygen, which makes it unstable. A stable secondary carbocation is formed. The electrons from the conjugate base attack the proton, henceforth, forming an alkene. Through this attack, the regeneration of the catalyst is formed with the product, 4-methylcyclohexene, before it oxidizes with KMnO4. In simpler terms, protonation of oxygen and the elimination of H+ with formation of alkene occurs.
Then the reaction tube was capped but not tightly. The tube then was placed in a sand bath reflux to heat it until a brown color was formed. Then the tube was taken out of the sand bath and allowed to cool to room temperature. Then the tube was shaken until a formation of a white solid at the bottom of the tube. After formation of the white solid, diphenyl ether (2 mL) was added to the solution and heated until the white solid was completely dissolved in the solution. After heating, the tube was cooled to room temperature. Then toluene (2 mL) was added to the solution. The tube was then placed in an ice bath. Then the solution was filtered via vacuum filtration, and there was a formation of a white solid. Then the product was dried and weighed. The Final product was hexaphenylbenzene (0.094 g, 0.176 mmol,
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
Results: Through a melting point reading, it was determined that the product obtained was 2,4-Dibromoanisol mp 55-58 C. The products obtained by my partners, were determined to be: (p-bromoacetanilide mp 160-165 C) and (2,4,6 tribromoaniline, mp of 108-110 C) respectively.
The IR spectrum RM-02-CC2 was obtained. The spectrum consisted of a carbonyl peak, an aromatic carbon-carbon double bond peak, and a sp2 hybridized carbon and hydrogen bond peak at 1713, 1598, and 734. These functional groups are all present in 9-flourenone. The carbonyl group specifically was important because fluorenone was the only that contained a carbonyl group. The Identity was further confirmed by the melting point, 79-80˚C. This value is similar to the known value 84˚C2. The melting point observed during the experiment is greater than the known because the sample is slightly impure. This impurity is caused by presence of fluorene on the tip of the columns. As stated before, the tip of the column needs to be manage to ensure pure products. The presence of fluorene would increase the temperature as seen in the melting point results because the melting point of this compound is greater than fluorenone. Overall, both compounds were separated with column chromatography and presented reasonable yields for both products. Column chromatography is a useful technique to separate mixtures with both large and small quantities. Unlike TLC, column chromatography and be used for large amounts of
...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.
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
Camphor is a trepenoid compound, meaning that it is derived from five-carbon isoprenes. Common uses of Camphor include insect repellent, fireworks and culinary purposes. In acetic acid, a secondary alcohol is converted to camphor following an oxidation reduction reaction. Sodium Borohydride is then used to give an isomeric alcohol, meaning that it has the same chemical formula as another molecule but has a different chemical structure. Since ketones can be easily reduced by metal hydrides such as LiALH4 and NaBH4, they are often used in reducing carbonyl groups. For this experiment sodium bromide is used as the reducing agent, which will reduce camphor to produce two products, namely borneol and isoborneol. For the reaction to
Based on the observed melting point range, the sample of Benzoic Acid was pure. The melting point range of the product read 122.5°C -123.2°C. The melting point fell within the melting point range of pure Benzoic Acid (121°C – 125°C), indicating both products are similar to one another. The melting point range of the sample was also very narrow (<1°C), indicating the sample was not comprised of any major impurities. Based on the observed melting point range, the sample of 2-naphthol was relatively pure. The sample’s melting point range (121.3°C – 122.6°C) was slightly below the range of pure 2-naphthol (123°C – 124°C), indicating the possibility of impurities. Yet, the melting point range of the sample was very narrow (≅1°C), indicating the sample was not comprised of any major impurities. Based on the observed melting point range, the sample of 1,4 – dimethoxybenzene was very impure. The sample’s melting point range (116.5°C – 120.9°C) was much higher than pure 1-4 dimethoxybenzene (58°C – 60°C), indicating major impurities within the sample. The wide observed melting point range also indicates a depressed melting point, leading to the conclusion that the compound is
This reaction is an example of the synthesis of a carboxylic acid utilizing a Grignard reagent. The reaction starts with the formation of a Grignard reagent; when the bromine on bromobenzene bonds to magnesium metal using the solvent, anhydrous diethyl ether. Using an ether is important due to the ability for its lone electron pairs help to stabilize the positive charge on magnesium. Once the Grignard reagent is obtained, the carbon, from the dry ice, will kick off the magnesium bromide and replace it. As this happens, water is reacted with it and thus adds a hydrogen onto the single bonded oxygen. Figure 1 shows the sublimation of dry ice with the Grignard reagent during this step. This will create an alcohol, specifically benzoic acid. After this step, the compound has replaced the magnesium bromide on the cyclohexane. In addition, biphenyl is produced as a side product. In the next step, addition of sodium hydroxide, the sodium will replace the hydrogen on the alcohol. Upon addition of HCl, the benzoic acid is freed from its salt and precipitates out of solution. Figure 3 shows the finished product of the Benzoic acid obtained. The product was a fine white powder.
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.
Once reaching a constant mass after driving of the excess diethyl ether, the crude product had a mass of 0.327grams and a high percent yield of 97.8%. During the first TLC examination of the crude product it was found to have 3 spots on the plate, biphenyl, benzaldehyde, and benzhydrol with Rf values of 0.68, 0.36, and 0.10 respectively. It was expected to see benzhydrol, the product, and biphenyl, the impurity, on the plate, but the presence of benzaldehyde was telling that not all of the starting material had been consumed during
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
The hydroxyl radical is the most important reactive species responsible for the destruction of the organic pollutant.
H. Fischer. Organic Syntheses Coll. 1943, 2, p. 202; H. Fischer. Organic Syntheses Coll. 1935, 15, p. 17.