Wittig Reaction Lab Report

There are several different reactions that can be used to synthesize an alkene product, however the main reaction being utilized for this experiment is the Wittig reaction and the Horner-Wadsworth-Emmons modification. The Wittig reaction involves a reaction between an aldehyde or ketone and ylid, which is also referred to as the Wittig reagent. The Wittig reagent is synthesized from a phosphonium salt and a strong base (Wittig Reaction, 2006). The reaction between the Wittig reagent and the ketone or aldehyde is a nucleophilic substitution; the carbon double bonded to the oxygen in the carbonyl is replaced with a carbon double bonded to another carbon (University of Liverpool, 2008). The Horner-Wadsworth-Emmons modification helped assure

Take an initial TLC and then add a magnetic stirring bar and begin stirring. Once stirring begins add 0.4 mL of 50% sodium hydroxide and allow mixture to stir for 30 minutes and once time is met take a second TLC. Once reaction is complete, determined by disappearance of aldehyde on TLC, add 1.5 mL of dichloromethane and water and allow solution to separate, followed by the extraction of the organic layer and placed into another vial. The remaining aqueous layer is mixed with 1.0 mL of dichloromethane to assure all of organic is removed and then the the combined organic layers is dried with calcium chloride and the solvent is removed using a vacuum filter. The collected solid is then dissolved in 1.0 mL of 1-propanol using heat and then is allowed to crystalize. The final product is the collected, and analyzed using percent yield and IR. The theoretical yield for trans-9-(2-phenylethenyl)anthracene was 0.1562g; the actual yield was 0.088 grams making the percent yield 56%. There were three different TLCs taken each one indicating the progress of the reaction. The first TLC indicated two regents present, 9-(2-phenylethenyl)anthracene and 9-anthraldehyde or the starting materials. The second TLC indicated that there were three reagents; in addition to the starting materials there is also product. The last TLC indicated there were compounds present, which