Wittig Reaction Lab Report

The chemical yield is a measurement of how efficient the organic reactant was synthesized into the desired product. The chemical yield will be lower if there are unreacted reactants or too many side products in the reaction. Unless the product was isolated properly during the distillation, it will negatively affect the chemical yield too. The chemical yield is measured by dividing the number of moles of product to the number of moles of reactant then multiplying it by 100 to get the percentage.

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

The dehydration of 2-methyl-2-butanol was performed using sulfuric acid and phosphoric acid in order to synthesize alkene products 2-methyl-1-butene and 2-methyl-2-butene. After carrying out steam distillation to isolate the organic alkenes from aqueous components within the reaction mixture, the purity and characterization of the products were then assessed through various analytical methods including Gas Chromatography (GC), Infrared Radiation (IR) Spectroscopy, and Nuclear Magnetic Resonance (NMR) Imaging. Through the characterization of the final products, it was found that little impurities remained in the final reaction solution and according to the GC, no alcohol remained in the vial after the reaction was complete. The actual yield

The purpose of this experiment is to convert carbonyl compounds to alkenes using Wittig reaction. In this case we will be synthesizing Trans-9-(2-phenylethenyl) anthracene from benzyltriphenylphosphonium chloride and 9-anthraldehyde. We will also aim to obtaining a high percent yield and purity for the synthesis of Trans-9-(2-phenylethenyl) anthracene. The mechanism for this reaction goes thus:

The bromination of the alkane was calculated and the overall percent yield was 96.35% with the percent yield with the calculated theoretical yield was 79.85%. The addition reaction was synthesized with a mechanism using 3 steps. The E-Stilbene reacted with pyridinium hydromide perbromide to form the pure (1R, 2S)-stilbene dibromide. One of the two diastereomeric products, the other would be dl(1R,2R + 1S,2S) stilbene dibromide.

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.

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 Hydroxyl group on alcohols relates to their reactivity. This concept was explored by answering the question “Does each alcohol undergo halogenation and controlled oxidation?” . Using three isomers of butanol; the primary 1-butanol, the secondary 2-butanol and the tertiary 2-methyl-2-propanol, also referred to as T-butanol, two experiments were performed to test the capabilities of the alcohols. When mixed with hydrochloric acid in a glass test tube, the primary alcohol and secondary alcohols were expected to halogenate, however the secondary and tertiary ended up doing so. This may have been because of the orientation of the Hydroxyl group when butanol is in a different

Purpose: The purpose of this lab is to further observe four types of chemical reactions. This lab will show four types of distinct chemical reactions and will increase my knowledge on each type.

After 10 minutes the reaction liquid was separated from the solid using a vacuum filtration system and toluene. The product was stored and dried until week 2 of the experiment. The product was weighed to be 0.31 g. Percent yield was calculated to be 38.75%. IR spectra data was conducted for the two starting materials and of the product. Melting point determination was performed on the product and proton NMR spectrum was given. The IR spectrum revealed peaks at 1720 cm-1, which indicated the presence of a lactone group, and 1730 cm-1, representing a functional group of a carboxylic acid (C=O), and 3300cm-1, indicating the presence of an alcohol group (O-H). All three peaks correspond with the desired product. A second TLC using the same mobile and stationary phase as the first was performed and revealed Rf Values of 0.17 and 0.43for the product. The first value was unique to the product indicating that the Diels-Alder reaction was successful. The other Rf value of 0.43 matched that of maleic anhydride indicating some

The purpose of this experiment was to perform a wittig reaction, the horner-emmons wittig specifically, reacting an aldehyde with an ylide to make an alkene. This particular variation of the wittig reaction has several advantages: It gives only the trans product; it uses a much milder base that is easier to handle; and it gives a water soluble byproduct which is easy to separate from the product. The reason that these advantages occur is a change in the structure of the ylide. Instead of a tripheylphosphine ylide, we use a diethylphosphonate ylide. The protons are much more acidic and its byproduct is negatively charged.

The objective of this experiment is to successfully perform a dehydration of 1-butanol and 2-butanol, also dehydrobromination of 1-bromobutane and 2-bromobutane to form the alkene products 1-butene, trans-2-butene, and cis-2-butene. The dehydration reactions react under and acid-catalysis which follows an E1 mechanism. It was found that dehydration of 1-butanol yielded 3.84% cis-2-butene, 81.83% trans-2-butene, and 14.33% 1-butene, while 2-butanol is unknown due to mechanical issues with the GC machine. For the dehydrobromination, with the addition of a

In this experiment, meso-stilbene dibromide was used to produce diphenylacetylene through two sequential dehydrohalogenations. The first part is a concerted E2 mechanism, where the reactant is deprotonated at the beta carbon from the halide ion that will be leaving. This creates a transition state where the leaving hydrogen and halide are anti-periplanar with each other, meaning that they are at a 180° angle in relation to one another. This reaction is caused by a base—in this case, potassium hydroxide—and produces a haloalkene, or vinyl halide. Potassium hydroxide was only added to reaction when needed, as

Reaction 1 involved a primary alcohol (OH), weak leaving group in the starting material and a reaction with a strong nucleophile (sodium bromide) and a polar protic solvent (sulfuric acid). The reaction was carried out through reflux and the product had a relatively high yield (75%) (Scheme 1).

Part 2 to determine the empirical formula and percentage yield of the compound synthesized in Part 1. Spectrophotometry is a routine laboratory test that has the added advantage