CHED 793 |
| Kristen Meldi, Heather Craig, and Jacqueline Bennett. The Walter H. Hoffman Department of Chemistry, Drury University, 900 N. Benton, Springfield, MO 65802 |
| Asymmetric synthesis is still a rarity in the undergraduate chemistry laboratory. In this experiment, asymmetric Mannich reactions, adapted from Chowdari, Ramachary, and Barbas III (2003), were designed to be completed in weekly, three-hour increments so as to be appropriate for sophomore-level organic chemistry laboratory. In the two-component reaction, the imine reagent was prepared by combining a toluene solution of ethyl glyoxylate and p-anisidine in the presence of molecular sieves. Toluene was removed by distillation and deemed suitable for reuse by NMR spectroscopy. The imine was then stirred with cis-4-decenal for 30 minutes in an ionic liquid solvent ([bmim]BF4) using L-proline as a catalyst. A one-step three-component Mannich reaction was also performed using the same solvent and catalyst system. The reaction mixture consisting of acetone, benzyloxyacetaldehyde, and p-anisidine was stirred for one hour at room temperature. Both Mannich reaction products were isolated by ether extraction. The products were analyzed by NMR and GCMS to reveal relatively pure samples. Polarimetry was used to determine ee. The significance of these experiments is their simplicity in which they introduce asymmetric synthesis as well as environmental friendliness, particularly the reusability of the ionic solvent and toluene. |
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Undergraduate Research Poster Session: Organic Chemistry
2:00 PM-4:00 PM, Monday, March 29, 2004 Anaheim Convention Center -- Hall A, Poster
Division of Chemical Education |