Lab #24-
Preparation 4-Methylcyclohexene
Introduction: The goals in this lab were to have a reaction occur with 4-methylcyclohexanol and an acid catalyst to form our product of 4-methylcyclohexene via an E1 reaction. This reaction is accomplished by removing the –OH group on 4-methylcyclohexanol via dehydration and to have a double bond form via a loss of a hydrogen on a β-Carbon. Many techniques and skills were developed in this lab. Among them were dehydration, isolation, drying, and distillation. We used all of these techniques to get the product we were looking for. In addition to these experimental techniques we also verified our product via spectroscopy which is a new technique. Using IR spectroscopy we were able to
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2) What major alkene product is produced by the dehydration of the following alcohols? a. Cyclohexanol = Cyclohexene b. 1-Methylcyclohexanol = 1-Methylcyclohexene c. 2-Methylcyclohexanol = 1-Methylcyclohexene d. 2,2-dimethylcyclohexanol = 1,2-dimethylcyclohexene e. 1,2-Cyclohexanediol = Cyclohexanone (pinacolone) 3) Compare and interpret the infrared spectra of 4-methylcyclohexene and 4-methylcyclohexanol - They both have very similar spectra. The biggest difference comes in the –OH group. On 4-methylcyclohexanol there is a large, broad –OH stretch at 3300 cm-1. In addition to that 4-methylcyclohexene has a C=C stretch at 1650 cm-1 that 4-methylcyclohexanol will not have since there is no double bond in it. 4) Identify the C-H out-of-plane bending vibrations in the IR spectrum of 4-methylcyclohexene. What structural information can be obtained from these bands? - The C-H bonds in this structure are shown at 1444 and 1368cm-1. These two bands indicate the two different types of C-H bends that occur on the molecule. One is that of the alkene and the other is that of the several alkanes on the molecule. 5) 1-2 mL of saturated sodium chloride was used to transfer the
There are millions of different organic compounds. Most of them are found in mixtures and in order to achieve a pure form they need to be separated, isolated, and purified. However, there are endless numbers of possible mixtures, which make it impossible to have a pre-designed procedure for every mixture. So chemists often have to make their own procedures. The purpose of this experiment was to prepare the student to the real world by them designing their own procedure which will help them understand the techniques of separation and purification better. The goal was to extract two of the components of the
The purpose of this lab was to carry out a dehydration reaction of 2-methylcyclohexanol by heating it in the presence of phosphoric acid and determining which alkene product would be the major product. Methylcyclohexanols were dehydrated in an 85% phosphoric acid mixture to yield the minor and major alkene product by elimination reaction, specifically E1. The alkenes were distilled to separate the major and minor products and gas chromatography was used to analyze the results and accuracy of the experiment. The hypothesis was the major product of the reaction would be the most substituted product. This conclusion was made because of
In conclusion, this lab was a failure. Not only was the yield very small upon inspection, but the product’s composition was unknown due to the unknown solution. Given the nature of the lab, little yield was expected and observed, making the lab itself very particular in nature. Add to this the addition of the unknown solution and any produce was astounding. Not only unfortunate, the unknown solution was very dangerous. If it had been some solution that reacted violently with the reagents, there could have been unforeseen damage done to the lab and the individuals
The objective of this lab was to create a ketone through an oxidation reaction using a using a secondary alcohol and oxidizing agent in order to use that ketone in a reduction reaction with a specific reducing agent to determine the affect of that reducing agent on the diastereoselectivity of the product. In the first part of this experiment, 4-tert-butylcyclohexanol was reacted with NaOCl, an oxidizing agent, and acetic acid to form 4-tert-butylcyclohexanone. In the second part of this experiment, 4-tert-butylcyclohexanone was reacted with a reducing agent, either NaBH4 in EtOH or Al(OiPr)3 in iPrOH, to form the product 4-tert-butylcyclohexanol. 1H NMR spectroscopy was used to determine the cis:trans ratio of the OH relative to the tert-butyl group in the product formed from the reduction reaction with each reducing agent. Thin-layer chromatography was used in both the oxidation and reduction steps to ensure that each reaction ran to completion.
Also, when looking at the filtrate values under the short-wavelength, a value of 0.44 appears to hint at the existence of the cis,trans-isomer which has a literature value of 0.41. The three values for the filtrate under the long-wavelength make sense as well, being that the value of 0.28 belongs to the oxide, the 0.36 to the trans,trans, and the 0.44 to the cis,trans.
There are four main regions of IR absorptions: region 4000 – 3000 cm-1 corresponds to N-H, C-H and O-H stretching, region 2250- 2100 cm-1 is triple-bond stretching , region 2000- 1500 cm-1 is double bonds and the region below 1500 cm-1 is the fingerprint region where a variety of single bonds are absorbed.3 The chromic acid test is a test for oxidizability and gives a positive result for primary and secondary alcohols as well as aldehydes2. A positive result in the chromic acid test is indicated by a color change and the formation of a precipitate. Tertiary alcohols give negative results for the chromic acid test since there must be a hydrogen present on the alcoholic carbon for oxidation to occur. The 2,4 DNP test, tests for a carbonyl and is therefore a dependable test for aldehydes and ketones. Finally, 13C NMR spectroscopy is a test to determine the structure of a compound. 13C NMR detects the 13C isotope of carbon. Each carbon has a different chemical shift. A carbon’s chemical shift is affected by the electronegativity of nearby atoms. Carbons that are bonded to highly electronegative atoms resonant downfield because the electronegative atom pulls electrons away from the nearby carbons and cause those carbons to resonant downfield1 (John McMurry, 2008). A general trend is that sp3-hybridized carbons absorb from 0 to 90 ppm, sp2-hybridized carbons resonant between 110
Experiment 55 consists of devising a separation and purification scheme for a three component mixture. The overall objective is to isolate in pure form two of the three compounds. This was done using extraction, solubility, crystallization and vacuum filtration. The experiment was carried out two times, both of which were successful.
Introduction: The fundamental techniques of organic chemistry lab, commonly known as SIPCAn, include separation, isolation, purification, characterization, and analysis (1). Through SIPCAn, students learn the fundamental techniques of organic chemistry laboratory. Mastering these techniques are necessary in order to perform more complicated experiments and to carry out organic reactions and synthesis. The information gained from SIPCAn included boiling point, melting point, and density can be used to identify unknown compounds. Simple distillation was used to purify a compound by separating it from a
group. The location of this hydroxyl functional group will impact the molecular structure of the
[〖(CH〗_3 ) _2 NC_6 H_4 ] _3 C^+ + OH^- → 〖(CH〗_3 )_2 NC_6 H_4 ]_3
14 mL of 9 M H2SO4 was added to the separatory funnel and the mixture was shaken. The layers were given a small amount of time to separate. The remaining n-butyl alcohol was extracted by the H2SO4 solution therefore, there was only one organic top layer. The lower aqueous layer was drained and discarded. 14 mL of H2O was added to the separatory funnel. A stopper was placed on the separatory funnel and it was shaken while being vented occasionally. The layers separated and the lower layer which contained the n-butyl bromide was drained into a smaller beaker. The aqueous layer was then discarded after ensuring that the correct layer had been saved by completing the "water drop test" (adding a drop of water to the drained liquid and if the water dissolves, it confirms that it is an aqueous layer). The alkyl halide was then returned to the separatory funnel. 14 mL of saturated aqeous sodium bicarbonate was added a little at a time while the separatory funnel was being swirled. A stopper was placed on the funnel and it was shaken for 1 minute while being vented frequently to relieve any pressure that was being produced. The lower alkyl halide layer was drained into a dry Erlenmeyer flask and 1.0 g of anhydrous calcium chloride was added to dry the solution. A stopper was placed on the Erlenmeyer flask and the contents were swirled until the liquid was clear. For the distillation
Bands that are the same is Root A and Shoot C. They both have the same size 0.2 and positive charge; making them the same isoenzyme. I am very certain of this because when the experiment was conducted I used a ruler to find the measurements and confirmed my data with partners and TA.
Another isomer of 1,4-dimethylcyclohexane is the cis isomer. Cis and trans isomers are diastereoisomers. It is impossible for them to be readily interconverted by a simple rotational process as they are identical conformations of the same isomer. In cis isomer, one methyl group is equatorial while the other one is axial. Chair flipping simply provides
1,7-octadiene yields cyclohexene and ethylene in a metathesis reaction through a ring closing mechanism (RCM). For the experiment, 1,7-octadiene was taken along with 1,1,8,8-tetradeutero-1,7-octadiene, that is, 1,7-octadiene with all the terminal hydrogens replaced with deuterium.