Alkene Essays

8 February 2017 Dehydration of 2-methylcyclohexanol Introduction: Dehydration is a common reaction in Organic Chemistry used to produce carbon-carbon double bonds. The dehydration mechanism involves the removal of water from an alcohol to form an alkene. In this experiment, 2-methylcyclohexanol will undergo acid catalyzed dehydration in heat to form three products: 1-methylcyclohexene, 3-methylcyclohexene, and methylenecyclohexane [1]. The reaction is carried out in a Hickman still filled with Drierite

Experiment 12: Dehydrobromination Discussion In this experiment, a double elimination reaction was performed on meso-stilbene dibromide, to form diphenylacetylene by eliminating two hydrogen and two bromine atoms in he presence of potassium hydroxide. The product was filtered and identified by comparing melting point data, and percent yield was calculated. Since an E2 reaction was performed in this experiment, the ideal conformation for the hydrogen and bromine would have been anticoplanar. However

There are several different reactions that can be used to synthesize an alkene product, however the main reaction being utilized for this experiment is the Wittig reaction and the Horner-Wadsworth-Emmons modification. The Wittig reaction involves a reaction between an aldehyde or ketone and ylid, which is also referred to as the Wittig reagent. The Wittig reagent is synthesized from a phosphonium salt and a strong base (Wittig Reaction, 2006). The reaction between the Wittig reagent and the ketone

2. In the contest of these two reactions, which is the better nucleophile, chloride ion or bromide ion? Try to explain this. Bromine is a better nucleophile. The chloride ion is more polar since it is above bromine on the periodic table and is more prone to hydrogen bonding due to its smaller size. Chloride ions are worse than bromine ions for nucleophilic attack, because the chloride ions are fully solvated and are not as available to attack. This is why Bromine ion is better nucleophile because

In this experiment, the bromination of E-Stilbene, or trans 1, 2 diphenylethene was performed in order to figure out whether the cation intermediate in the mechanism was cyclic or acyclic. The hypothesis was that if the product of the reaction was 100% meso- 1,2-dibromo-1,2-diphenylethane, or meso-stilbene dibromide, the intermediate was cyclic, but if there was a 50:25:25 ration of meso, D, and L isomers, the intermediate was acyclic. In the mechanism with the cyclic intermediate, the pi electrons

done quickly do to the fact that it the proton antiperiplanar to the leaving group which is the bromide. The bond between the proton and the carbon shifted between the two carbons to form a double bond. Bromine became the leaving group so that the alkene could be formed which is known as (E)-1-Bromo-1,2-diphenylethylene. Another elimination reaction occurred with the product still being in the KOH. This reaction is done

The Diels-Alder reaction, an electrocyclic reaction between a conjugated diene and a substituted alkene, also known as a dienophile, was used in the experiment. The purpose was to synthesize a substituted cyclohexene derivate by the reaction between the diene and dienophile, and it reacted in a reflux solution with toluene as the solvent forming an unsaturated six-membered ring. First, approximately 54 mg each of both compounds, tetraphenylcyclopentadienone (TPCPD) and diphenylacetylene (DPA), were

Chemistry Exploration Topic: determining the activation energy of a chemical reaction Research Question: What effect does temperature of the chemical reaction have on the activation energy ? ICT: Microsoft Word Autograph Microsoft Excel Introduction This experiment is designed to help in estimating the activation energy of the rate-limiting step in the acid catalyzed reaction of acetone with iodine. This is achieved by measuring the reaction rates at different reaction temperatures over

Nucleophilic Substitution: Preparation of 1-Bromobutane and Alkyl Halide Classification Tests Introduction This procedure was undertaken in order to convert a primary alcohol, 1-butanol, into a primary alkyl halide, 1-bromobutane. This was done using hydrobromic acid. Additionally, tests were performed to assess the degree of the alkyl halide: primary, secondary or tertiary. These tests were the silver nitrate test and the sodium iodide test. The goal of these tests was to verify that 1-bromobutane

On 1/7, the Alky started to only process FCCU BB and no longer process Coker BB. Alkylation chemistry, neither likes contaminants nor diluents. Contaminants are direct acid consumers. The more contaminants in the feed, the more often the unit will be at an acid constraint. Diluents do not react in alkylation chemistry, but they take up space and decrease the effective area for isobutane and olefin to contact. With less contact, side reactions like polymerization are more likely to occur; polymerization

Introduction The experiments in this lab each involved a Diels-Alder reaction. A Diels-Alder reaction is a one-step reaction between a conjugated diene and a dienophile. The Diels-Alder reaction is exothermic. In the reaction, the bonding electrons rotate to form carbon-carbon bonds which then create a cyclohexane ring product. The product can be exo or endo. The endo product is the major product since they are the more favored kinetically. In order for a Diels-Alder reaction to occur, the diene

Discussion This experiment done in lab was the Bromination of (E)-Stilbene to produce dibromide stilbene. Though there are three products, the meso-stilbene product is the major product. In order to get theunderstand how to get the correct major product, the full mechanism must be done. In order to achieve the meso product, the double bond in between the carbons attackss molecular bromine which in turn breaks the bromine-bromine bond. The attacked bromine forms a cyclic bridged bromine ion intermediate

The hydration of an alkene leads to the formation of an alcohol as a result of the acid-catalyzed addition of water to the double bond. This reaction mechanism is an equilibrium reaction as the forward reaction is the hydration of the alkene, and the reverse reaction is the dehydration of the alkene. Whether the equilibrium will favor the forward or reverse reaction is dependent on the conditions of the reaction. Excess water will drive the equilibrium forward as the double bond undergoes hydration

Using this information to analyze the alkene peaks of the NMR spectra of the reactions using NaOH, KOH, or LiOH, one can conclude that the counter ion of the base used had no effect on the stereochemistry of the alkene formed from all three Wittig reactions ran in lab: all the NMR spectra show the same trans-alkene. Since there are two alkene protons in the product formed from all three Wittig reactions, there are two sets of peaks in the alkene region of the three NMR spectra. The two larger

elimination, which is removing H-X substituent to form a double bonds. The mechanism of E1 reaction includes 2 steps, formation of carbocation and deprotonation. E2 is bimolecular elimination, which is the removal of two substituent groups to form an alkene. The hydrogen removed must be anti to the leaving group. The mechanism of E2 reaction has only one steps, which is displacement of leaving group by removing hydrogen. The rate of the E1 elimination is based on substrate only, while it depends on both

electrophilic carbon. In this case, KOtBu is a strong, bulky base and -Br is a good leaving group. Although the Potassium is not crucial to this reaction, the t-butoxide will proceed to attack the single beta hydrogen and knock off bromide to form an alkene, rearranging the bromobutane into an anti-periplanar position. In the KOtBu and 1-bromobutane reaction, there is one beta hydrogen present; this means there is only one possible product, 1-butene. However, there are two different types of beta hydrogens

identified using gas chromatography. An acid-catalyzed dehydration of 2-methylcyclohexanol occurs via an E1 mechanism; acids will react with 2-methylcyclohexanol to eliminate the alcohol (OH group). This causes the formation of a carbocation and an alkene will form near the charge. Based on the position of the charge, two or three products can be produced. After the protonation of the alcohol group on 2-methylcyclohexanol, resulting in water (good leaving group), a double bond will form, producing

the two products creates a cyclic product. The conjugated diene (called diene) was anthracene (consisted of 2 double bonds) and the dienopile was maleic anhydride (consisted of 1 double bond). The reaction occured between the alkene group of maleic anhydride and the alkene group of anthracene. The reaction is: Source: Melvil, 2014. The solvent used was xylene (dimethyl benzene) and the reactants were boiled in it. Since the boiling point for xylene is high, it assisted in the reaction proceeding

Classification test were performed. The Bromine test and Permanganate test were used to determine if alkenes were indeed present in the solution. Both test were positive for the compound. During the Bromine test, the bromine transformed from brown to clear indicating the presence of an alkene. Also during the permanganate test, the compound changed from purple to brown. This also indicates the presence of an alkene, which indicates the E2 reaction did occur. These two positive test allowed for a GC spectrum

control was used to compare the reactant and the product, showing a clear appearance that would indicate an alkene being present. Bromine was added to the reactant 4-methylcyclohexanol, and a reddish-brown color appeared, indicating that no reaction took place. Bromine was then added to the product 4-methylcyclohexene, and the clear appearance of the product remained, concluding that an alkene is indeed present. Discussion Given the results obtained post-experiment, the percent yield was calculated