Wednesday, September 11, 2019

Evaluation of L-Proline as a Catalyst for an Asymmetric Aldol Reaction Lab Report

Evaluation of L-Proline as a Catalyst for an Asymmetric Aldol Reaction - Lab Report Example The product was then extracted with 10mL of ethyl acetate. Drying was done over MgSO4 . the separation of the drying agent was done via gravity filtration, whereas that of the solvent was done through rotary evaporation. The product was further taken through purification steps, which involved the use of flash chromatography using 50% petroleum ether/ 50% ethyl acetate as the eluting solvent. The fractions were then combined and the solvent eliminated via evaporation method. The massed of the obtained products were then recorded, and verification obtained. To conduct the Mosher analysis, 15mg of the Aldol product were dissolved in 0.9mL of anhydrous CH2Cl2 in a flame dried vial. 1.5mg of 4-dimethylaminopyridine (DMAO) followed by 15á ´ «L pyridine and MTPA-Cl were added. The solution was then sealed and allowed to react under nitrogen. After the reaction was complete, the isolation process followed. The crude reacrion was washed with 0.1 N HCL (0.5 mL), saturated bicarbonate solution (0.5 mL) and brine (0.5mL). The ratio of diastereomers by H-NMR was determined and enantiomeric excess of the Aldol reaction computed. From the analysis of the results obtained from the experimentation, it was clear that L-proline functions as a catalyst in a reaction involving Aldol. The product was further quantified by use of the Mosher ester approach. Consequently, a conclusion was drawn that L-proline functions as a catalyst in Aldol reactions. One of the powerful methods through which carbon-carbon bonds can be formed is through nucleophilic addition of an enolate to a carbonyl group. An example of the scenarios in which this principle has been applied is in the de novo generation of carbohydrates which results from the development of aldolase enzymes, which catalyze biological Aldol reactions. The ability of aldolases to produce enantiomeric product exclusively is a notable feature, difficult for the modern synthesis

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