Introduction During this week’s lab, both the cis and trans enantiomers of 2-methylcyclohexanol will be produced through the reduction of 2-methyclcyclohexanone with sodium borohydride. Once the product is formed, NMR signals are used to examine the product of this reduction by observing the cis and trans location of the CH2OH group. The integration of the signal will then be examined and to show the ratio of cis and trans product that is formed through this reaction. Experimental Procedure For this lab, the first step is to add 2.5mL of methanol to .595g of 2-methylcyclohexanone inside a large test tube and then cool it in an ice bath. Once combined, add 0.1g of sodium borohydride to the test tube and once the reaction stops take the
The purpose of this experiment is to determine the absolute configuration of an unknown chiral secondary alcohol using the competing enantioselective conversion (CEC) method. This method uses both R- and S- enantiomers of a chiral acyl-transfer catalyst called homobenzotetramisole (HBTM), in separate parallel reactions, and thin layer chromatography to identify the stereochemistry of the secondary alcohol, whether it be an R- or S- enantiomer. Quantitative analysis was performed using a program called ImageJ after the appropriate picture was taken of the stained TLC plate. The molecular structure of the unknown alcohol was identified using 1H NMR spectroscopy by matching the hydrogens to the corresponding peak.
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
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.
Each subsequent trial will use one gram more. 2.Put baking soda into reaction vessel. 3.Measure 40 mL vinegar. 4.Completely fill 1000 mL graduated cylinder with water.
This week’s lab was the third and final step in a multi-step synthesis reaction. The starting material of this week was benzil and 1,3- diphenylacetone was added along with a strong base, KOH, to form the product tetraphenylcyclopentadienone. The product was confirmed to be tetraphenylcyclopentadienone based of the color of the product, the IR spectrum, and the mechanism of the reaction. The product of the reaction was a dark purple/black color, which corresponds to literature colors of tetraphenylcyclopentadienone. The tetraphenylcyclopentadienone product was a deep purple/black because of its absorption of all light wavelengths. The conjugated aromatic rings in the product create a delocalized pi electron system and the electrons are excited
3.) Divide your 30g of white substance into the 4 test tubes evenly. You should put 7.5g into each test tube along with the water.
The procedure of the lab on day one was to get a ring stand and clamp, then put the substance in the test tube. Then put the test tube in the clamp and then get a Bunsen burner. After that put the Bunsen burner underneath the test tube to heat it. The procedure of the lab for day two was almost exactly the same, except the substances that were used were different. The
For this experiment, you will add the measured amount of the first sample to the measured amount of the second sample into its respectively labeled test tube then observe if a reaction occurs. In your Data Table, record the samples added to each test tube, describe the reaction observed, if any, and whether or not a chemical reaction took place.
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
2. In the large beaker, put water and boil it completely. After that, remove the beaker from heat. 3. Sample tubes (A-D) should be labeled and capped tightly.
Tilt the test tube or glass, and slowly add an equal amount of the cold alcohol by pouring the alcohol down the sides of the test tube. Wait 20 minutes.
The obtained NMR spectra was very similar to that of the predicted results. The methyl hydrogen group had a single peak at 2.153 ppm. The results were a little off from the predicted shift of 2.2 – 2.9 ppm but not by much. Next in the spectra, were the hydrogens in the aromatic ring with a range of 7.065-7.436 ppm consisting of multiple peaks, these also matched up to the predicted shift of 6.5-8.0 ppm. The last signal belonged to that of the hydrogen in the amide that had a peak at 7.571 ppm which is well in the range of the predicted shift it 5.0 – 9.0 ppm. Overall the NMR proved that the purified acetanilide had very little impurities shown in the
(10) We learned how to extract and partially “clean” DNA from fruit flies, Inversion polymorphism associated with the ebony phenotype.
== § Test tubes X 11 § 0.10 molar dm -3 Copper (II) Sulphate solution § distilled water § egg albumen from 3 eggs. § Syringe X 12 § colorimeter § tripod § 100ml beaker § Bunsen burner § test tube holder § safety glasses § gloves § test tube pen § test tube method = == = =
tube. Add 6 mL of 0.1M HCl to the first test tube, then 0.1M KMnO4 and