In a typical example, 1 g c-PEO-OH was dissolved in 30 mL anhydrous N-Methyl-2-pyrrolidone (NMP) solvent under dry argon atmosphere, to which 10 mL 2-bromoisobutyryl bromide was added at 0 °C dropwise for 30 min under vigorous stirring. The reaction mixture was then allowed to proceed at room temperature for 1 d. After that, the solution was concentrated by reduced pressure distillation to remove NMP solvent and excess 2-bromoisobutyryl bromide. The crude product was then washed with saturated aqueous solution of NaHCO3 and water sequentially for 3 times, dried over MgSO4, and precipitated in cold n-hexane to obtain a final brown viscous product. Preparation of c-PEO-N3 by substituting the Br on c-PEO-Br with azide functionalities…
Sterols in plants are almost completely derived from acetyl-coenzyme A (acetyl-CoA). Acetyl-CoA is dimerized to acetoacetyl-CoA that then forms 3- hydroxy-3-methylglutaryl-CoA (HMG-CoA) by a condensation reaction. HMG-CoA is reduced to mevalonic acid by 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), a rate-limiting step in human isoprenoid biosynthesis. HMGR over-expression in transgenic tobacco plants resulted in increased levels of total sterols, indicating that HMGR is a limiting enzyme also in plant sterol biosynthesis (Schaller et al., 1995). The next step in sterol synthesis is to form squalene from mevalonic acid, and this is performend by a series of reactions where the final step is catalysed by the squalene synthase enzyme (SQS).…
Discussion: Spinacia oleracea like many other plants contains leaves which play a crucial role in the process of photosynthesis. The energy used to drive the chemical reactions within photosynthesis comes from the sunlight absorbed by the chlorophyll molecules (Merzlyak, Chivkunova, Zhigalova, & Naqvi 2009). These chlorophyll molecules then transfer the light energy to chloroplasts and that light energy is converted into chemical energy (Merzlyak, Chivkunova, Zhigalova, & Naqvi 2009).…
In the Acid-Catalyzed Hydration of norbornene, water and sulfuric acid were added to the C=C double bond to form norborneol. Sulfuric acid acted as a catalyst, where it was not consumed in the reaction and helped to propel the reaction forward, as it was vital in forming hydronium ion and breaking the double bond. Both the products endo-norborneol and exo-norborneol were synthesized; however regioselectivity and stereoselectivity played a role as to which product was more preferred and whether the equatorial or axial orientation of the hydroxy group was favored. The setup of the Cold-Finger, and the ability of norborneol to sublime readily allowed for the purification of the crude product to obtain the diastereomeric products exo- and endo-norborneol.…
Experiment 5 Synthesis and NMR Spectroscopy of ethyl cinnamate Introduction: Wittig reactions involve the stereoselective synthesis of olefins from phosphonium ylides and aldehydes or ketones, where the carbonyl bond is converted to an alkene double bond.1 The variety of suitable reagents and the relatively mild experimental conditions facilitate their industrial applications, such as the synthesis of epoxides, esters, carotenoids and vitamin A.2,3 Specifically, the ester ethyl cinnamate is used as a flavouring agent and in perfumes. The diastereomers of the alkene are distinguished through Proton Nuclear Magnetic Resonance (1H NMR) spectroscopy, where the coupling constants of alkenyl protons are different for (E) and (Z) isomers.4…
After starting with 30 mL of an unknown mixture of two solvents, fractional distillation and gas chromatography were used to identify the unknowns as acetone and toluene in a 1 to 2.04 ratio of acetone to toluene. Fractional distillation was first used to separate the unknown mixture into its components based on boiling point. Distillation refers to the method of separating components of a mixture through heating and cooling. Simple distillation, which is especially useful in the separation of less-volatile substances from volatile substances, such as sugar from water, can be used to separate a liquid-liquid mixture if the boiling points of the component liquids differ by more than 40-50°C. A plot of temperature versus volume for a simple…
One important aspect of organic chemistry is the synthesis of new compounds. It is also important for chemists to understand how to perform certain techniques, such as extraction and distillation, to produce the new products, which are usually drugs and cures for illnesses. In this experiment, n-butyl bromide was produced. n-Butyl bromide is an alkyl halide, which are usually synthesized by an alcohol and an acid. In the case of n-butyl bromide, n-butyl alcohol was used along with sodium bromide and sulfuric acid.…
Introduction The purpose of this experiment was to understand acid-catalyzed hydration of alkenes through the formation of exo-norborneol from the reaction of Norborene with acid and the excess of water. Acid-catalyzed hydration is useful in removing double and triple bonds; an unsaturated compound becomes reduced to a saturated compound in the presence of the acid catalyst, or water for this experiment. Hydration of alkenes is the result of acid-catalyzed addition of water to a carbon-carbon double bond. This leads to the formation of an alcohol.…
The purpose of this lab is to calculate the chemical formula of a hydrate compound made up of copper, chlorine, and water molecules by using the law of definite proportions. The water of hydration of the copper chloride hydrate sample will be determined as well as the mass of copper and chlorine through a chemical reaction. The results will be used to calculate the moles of copper and chlorine and then the empirical formula of the compound. Techniques used:…
Introduction Debates concerning the health effects of artificial sweeteners are relevant not only for scientists and dieticians, but also for diabetics and individuals who are trying to lose weight. According to the American Diabetes Association (2014), aspartame (Equal, NutraSweet); acesulfame potassium (Sunett, Sweet One); neotame; sucralose (Splenda); saccharin (Sweet ‘N Low, Sweet Twin, Sugar Twin); and advantame are six alternatives to natural sugar that are commonly added to foods and incorporated into store-bought foods. Rebaudioside A (Stevia) is a natural sweetener that is also quite common (para. 3, 5). The benefits of artificial sweeteners include their concentrated flavor and their low calorie content.…
Purpose: The purpose of this laboratory was to synthesize isopentyl acetate, commonly known as banana oil, in a reaction of methanol and isopentyl alcohol catalyzed by sulfuric acid. Through this Fischer esterification reaction, it was possible to learn about using a Reflux condenser to run a reaction as well as purifying the product through various washes and extractions along with simple distillation. In addition, the product of the experiment was carefully analyzed based upon boiling point, physical characteristics, IR and 1H NMR. The overall objective was to successfully isolate the product of isopentyl acetate and observe the purity of this product.…
Abstract: The objective of this experiment was to synthesize aspirin from salicylic acid and acetic anhydride. The general theory behind this experiment was to study the synthesis of a drug from organic materials. During the experiment, esterification had occurred between reactants salicylic acid and acetic anhydride. Then, phosphoric acid would catalyze the reaction and water would be added to decompose the remaining acetic anhydride. Through the process of filtration, aspirin crystals were collected and separate from the liquid acetic acid-water solution.…
Introductions: The purpose of this experiment is to synthesize acetaminophen and esters in order to apply the process of retrosynthetic analysis to determine the unknown alcohols used to produce the esters. Acetaminophen, a popular active ingredient in many over-the-counter drugs, is used as a pain reliever and a fever reducer. It is synthesized from the reaction between a carboxylic acid and an amine; thus, acetaminophen contains hydroxyl and amide functional groups.1 C6H7NO + C4H6O3 C8H9NO2 + C2H4O2 This reaction is commonly known as a condensation reaction.…
Experiment 5 Title: Mayonnaise production Objective: To determine the type of food emulsion obtained by varying the mixture sequence Introduction: A most important field of emulsion technology is that involving food preparations. Some of the oldest emulsions known to man, for example, butter, salad dressings and so on are included in this group, while the applications of emulsion theory to the baking process and to therapeutic feeding represent modern developments.…
Purpose: To test the effect of inorganic and organic catalyst concentration and surface area on the reaction rate. Introduction: In this experiment the experimenters will seek to determine what factors determine the rate of a reaction with a catalyst. A catalyst is a molecule that starts a chemical reaction, but it is not part of the reaction it is causing.…