Chemical Biology 3OA3, September 2009 Page 55 6. E XPERIMENTAL P ROCEDURE Week One: Diester synthesis. You will be organized into groups; your TA will tell you the structure you are to synthesize ahead of time. Make sure you have selected the appropriate starting alkyl meta- or para-hydroxybenzoate and acyl chloride to give the correct product. Diester Synthesis Place the appropriate monoester (250 mg) in a 25 mL round-bottom flask, and add 5 mL of dichloromethane (DCM), then 2 equivalents of triethylamine and finally 2 equivalents of acyl chloride. Attach a reflux condenser, and heat at reflux gently for 15 min. Remove from heat and, when cool, check the reaction by TLC, using the saved starting mono-ester, diluted in DCM, as a standard. If a significant amount of starting material is still present, heat for a further 30 min., then test again by TLC. Place the reaction mixture in a separatory funnel. Wash with 2 × 10 mL of 2 M HCl. (If there is precipitate before washing, add DCM, 1 mL at a time, until it is dissolved.)
This is the end of the preview.
access the rest of the document.