Alkyne Diphenylacetylene Lab Report

The literature values of erythro-2,3-dibromo-3-phenylpropanoic acid and threo-2,3-dibromo-3-phenylpropanoic acid were provided in the laboratory experiment text. Erythro-2,3-dibromo-phenylpropanoic acid held a melting point of 204°C, while threo-2,3-dibromo-3-phenylpropanoic acid held a melting point of 95°C. These two products had vastly different melting point values, which made it clear to observe the product created at the end of the experiment. Once the product was determined due to comparison of melting points, the stereochemistry could be

The mixture was transferred to an ice bath to crystallize the product, after which the product was collected by vacuum filtration on a Hirsch funnel, washing the flask with small aliquots of cold xylene and pouring the solution over the crystals, allowing the vacuum to thoroughly dry the product. Additional drying was achieved by transferring the product to filter paper and pressing the crystals to remove any excess moisture. The product was then weighed and a melting point determined. A comparative TLC was run in Hexanes:Ethyl Acetate solvent against maleic anhydride to verify the purity of the

Discussion: In the synthesis of 1-bromobutane alcohol is a poor leaving group; this problem is fixed by converting the OH group into H2O, which is a better leaving group. Depending on the structure of the alcohol it may undergo SN1 or SN2. Primary alky halides undergo SN2 reactions. 1- bromobutane is a primary alkyl halide, and may be synthesized by the acid-mediated reaction of a 1-butonaol with a bromide ion as a nucleophile. The proposed mechanism involves the initial formation of HBr in situ, the protonation of the alcohol by HBr, and the nucleophilic displacement by Br- to give the 1-bromobutane. In the reaction once the salts are dissolved and the mixture is gently heated with a reflux a noticeable reaction occurs with the development of two layers. When the distillation was clear the head temperature was around 115oC because the increased boiling point is caused by co-distillation of sulfuric acid and hydrobromic acid with water. When transferring allof the crude 1-bromobutane without the drying agent,

During the halogenation reactions of 1-butanol, 2-butanol, and 2-methyl-2-propanol, there is a formation of water from the OH atom of the alcohol, and the H atom from the HCl solution. The OH bond of the alcohol is then substituted with the Cl atom. Therefore all of the degrees of alcohol undergo halogenation reactions, and form alkyl halides as products. This is because the functional group of alkyl halides is a carbon-halogen bond. A common halogen is chlorine, as used in this experiment.

The carbon-carbon double bond of alkenes represents a site that has a high electron intensity. This site is susceptible to oxidation. Depending on the conditions or reagents used to initiate the oxidation of alkenes, various products can be obtained. With relative mild oxidation, it is only the pi bond of an alkene that is cleaved resulting in the production of 1,2-diols or epoxides. However, when there is more vigorous

The reaction involves a nucleophilic acyl substitution on an aldehyde, with the leaving group concurrently attacking another aldehyde in the second step. First the Potassium hydroxide attacks a carbonyl, which forms a tetahedral intermediate which then collapses when attacked by another hydroxide. The carbonyl is formed again when its hydride attacks another carbonyl. In the final step of the reaction, the acid and alkoxide ions formed exchange a proton. In the presence of a very high concentration of base, the aldehyde first forms a doubly charged anion from which a hydride ion is transferred to the second molecule of aldehyde to form carboxylate and alkoxide ions. Subsequently, the alkoxide ion acquires a proton from the solvent.

We used TLC analysis to identify each product obtained from the dihydroxylation reactions by spotting a TLC plate with the product of our reaction, a solution of cis-cyclohexane, trans-cyclohexane, and a 50:50 mixture of the two. We then placed the plate in a beaker with ethyl acetate saturating the atmosphere to allow the TLC plate to develop. Finally, we compared Rf values of the components of the mobile phase, after the phase was completed. 100% ethyl acetate was used instead of 100% Hexane or a mixture of Ethyl Acetate, because ethyl acetate has high polarity and can separate the components of a mixture to elution, unlike hexane, which is non-polar, and therefore unable to separate the components of the mixture. A 50:50 mixture of both would not work, because the polar and non-polar compounds would neutralize the mixture, and thereby not separate the components of the mixture.

You may have done siinple experiments alkene can be quickly and easily differentiated from an alkane. to learn how an identified, and

6. Purpose: to clarify the mechanism for the cycloaddition reaction between benzonitrile oxide and an alkene, and to test the regiochemistry of the reaction between benzonitrile oxide and styrene; to purify the crude product of either trans-stilbene, cis-stilbene, or styrene reaction.

The purpose of this experiment is to examine the reactivities of various alkyl halides under both SN2 and SN1 reaction conditions. The alkyl halides will be examined based on the substrate types and solvent the reaction takes place in.

Aromatic compounds can undergo electrophilic substitution reactions. In these reactions, the aromatic ring acts as a nucleophile (an electron pair donor) and reacts with an electrophilic reagent (an electron pair acceptor) resulting in the replacement of a hydrogen on the aromatic ring with the electrophile. Due to the fact that the conjugated 6π-electron system of the aromatic ring is so stable, the carbocation intermediate loses a proton to sustain the aromatic ring rather than reacting with a nucleophile. Ring substituents strongly influence the rate and position of electrophilic attack. Electron-donating groups on the benzene ring speed up the substitution process by stabilizing the carbocation intermediate. Electron-withdrawing groups, however, slow down the aromatic substitution because formation of the carbocation intermediate is more difficult. The electron-withdrawing group withdraws electron density from a species that is already positively charged making it very electron deficient. Therefore, electron-donating groups are considered to be “activating” and electron-withdrawing groups are “deactivating”. Activating substituents direct incoming groups to either the “ortho” or “para” positions. Deactivating substituents, with the exception of the halogens, direct incoming groups to the “meta” position. The experiment described above was an example of a specific electrophilic aromatic

An alcohol dehydration reaction is useful for synthesizing alkenes. Through the use of an acid catalyst, an alcohol is protonated and then dehydrated by the loss of a water molecule. This dehydration step results in a carbocation, and deprotonation by a base results in a final alkene product. In this experiment, 4-methylcyclohexene was obtained with a 32% yield. The theoretical yield of the product was 6.3 grams, but the actual yield of the product was 2.0 grams. A low percent yield of product could be attributed to systematic errors. An improperly tared scale, an inaccurately lined graduated cylinder, or a tiny crack in glassware could result in less than desirable product yields.

The boiling range of the 1-pentyl ethanoate distillate was approximately between 149-151°C. This was indicated by the formation of the distillate and when the mixture of the purified 1-pentyl ethanoate started to vigorously

The M-C3 and C1- C2 single bonds are broken to form a metal alkylidene and ethylene.

This activation bond, carbon-hydrogen, is currently at the edge of synthetic organic chemistry. Carbon-hydrogen activation allows the chemist to perform unexpected disconnection, and it enables synthetic strategies. Over the past thirty years, the Heck reaction has become a fundamental metal catalyzed carbon-carbon bond, which is able to form the process for the synthesis of molecules that