Stereochemistry Post Lab Report. Reference: Experimental

The objective of this laboratory experiment is to study both SN1 and SN2 reactions. The first part of the lab focuses on synthesizing 1-bromobutane from 1-butanol by using an SN2 mechanism. The obtained product will then be analyzed using infrared spectroscopy and refractive index. The second part of the lab concentrates on how different factors influence the rate of SN1 reactions. The factors that will be examined are the leaving group, Br – versus Cl-; the structure of the alkyl group, 3◦ versus 2◦; and the polarity of the solvent, 40 percent 2-propanol versus 60 percent 2-propanol.

The first TLC plate showed that the fractions collected during the experiment that appeared to be the purest were fractions 4 and 6. These two fractions and fractions number 5 were combined for the final product. The Rf values for the standard carvone, fraction 4, and fraction 6 were all 0.32 indicating that these compounds were

After placing in darkness the colorless solution resulted by reformation of the radical intermediates to a new thermodynamic product via C-N bond at room temperature. UV-Vis was conducted on the solution before and after the irradiation with sunlight: UVtoluene 554.92nm, A=0.12 before irradiation and A=1.05 after. The peak at 554.92nm corresponds to yellow/green light and its complementary colour is red/violet. This validates the solutions violet color. The increased absorbance was accounted for an increase in the radical component. The radical was formed when exposed to light, which was visually apparent with the purple coloration and proved the thermodynamic dimer was also photochromic. When dimer 4 is exposed to light photons collide with the molecule and impart energy upon them. This energy is significant enough to break the bond between the two rings and results

8. ISBN: 0-558-05245-2 Virtual ChemLab: General Chemistry, Student Lab Manual/Workbook, V. 2.5, Third Edition, by Brian F. Woodfield and

Introduction: I know prior to doing this experiment that iodine mixed with starch creates a dark color and that most objects, organic and inorganic, naturally experience isotonic reactions.

Within this experiment a type of cycloaddition reaction was performed, called Diels-Alder reaction. This type of reaction involves both a 1,3-diene and an alkene, called the dienophile in this reaction. Within this reaction two new sigma bonds were formed at the 1 and 4 carbon atoms of the diene. Two other pi bonds are also formed simultaneously with the sigma bonds. Due to this concerted nature of the reaction the diene must be able to adopt a s-cis configuration, making the reaction stereospecific.

Diels-Alder Reaction Objective: The objective of this experiment is to demonstrate a typical Diels-Alder reaction by reacting anthracene (diene) with maleic anhydride (dienophile) to produce 9,10-dihydroanthracene-9,10-α,β-succinc acid anhydride, the product. Scheme 1. Cycloaddition through the Diels-Alder Reaction1 Experimental: Anthracene (1.00 g, 5.61 x 10-3 mol), maleic anhydride, (0.75 g, 7.65 x 10-3 mol), and xylene (5.0 mL) were combined in a 10 mL long-necked, round-bottomed flask. A stir bar was added and an empty distillation column was attached to the flask to function as an air condenser. The mixture was refluxed for 40 minutes over a sand bath, ensuring the temperature was monitored to prevent the reflux ring from surpassing the

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

Dictionary of organic compounds, 6th edition, Chapman and Hall, London, Volume 3(& Volume 6), 1996 Maria Lindsay and Sean P. Hickey, Organic chemistry lab 2 manual, department of Chemistry University of New Orleans

Treatment of a racemic mixture with tartaric acid which is an optically pure resolving agent helped in the separation of the racemic mixture into the R and S diastereomer salts because of their unique solubilities with methanol (2). It was evident that both diastereomers had different solubilites in methanol because one diastereomer R-(+)-amine dissolved in the solution while the other, S-(-)-amine precipitated into crystals and did not dissolve. The crystals were purified and further isolated through a vacuum filtration (1). Below, shows the treatment of a racemic mixture with tartaric acid and methanol. As mentioned before, the resulting product is diastereomeric salts, which were separated based on solubility

Two different reactions had been performed and formed the cis and trans products. Isomers that are cis are defined as molecules that have higher priority groups both on same sides of a molecule. Molecules that have higher priority groups both on opposing sides are trans isomers. The compound 1,2-cyclohexanediol is formed using methydioxirane. This is a compound prepared using acetone as well as oxone.

Gilbert, John and Stephen F. Martin. Experiment Organic Chemistry: A Miniscale & Microscale Approach. Belmont, CA: Thomson Brooks/Cole, 2010. 537-547. Print.

In the method of continuous variations the total number of moles of reactants is kept constant for the series of measurements. Each measurement is made with a different mole ratio of reactants. A mole ratio is ratio between the amounts in moles of any two compounds involved in a chemical reaction. Mole ratios are used as conversion factors between products and reactants in many chemistry problems.

As a result, polar compounds have long retention times on polar stationary phases and shorter retention times on non-polar columns using the same temperature. Chiral stationary phases that are based on amino acid derivatives, cyclodextrins and chiral silanes are capable of separating enantiomers because one enantiomer interacts slightly stronger than the other one with the stationary phase, often due to steric effects or other very specific interactions. For instance, a modified -cyclodextrin column is used in the determination of the enantiomeric excess in the chiral epoxidation experiment (Chem

This lab consisted of formulating a mechanism by which dimethyl maleate (cis confirmation) could be isomerized to dimethyl fumarate (trans confirmation) by heat, light, or bromine. In order to investigate chemical properties of when the molecule is in a chiral vs. achiral environment, enantiomers of carvones were compared.