Honors Cup Synthetic Proposal (271 III-Th PM-W08)

Transcription

1 onors Cup Synthetic Proposal (271 III-Th PM-W08) Section: 271 Group Members: Eric Chen, Yue Ding, Rebecca Lee, Alexander Sapick Title: Synthesis of Camphor from Camphene Introduction: 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (Camphor) can be synthetically produced from Camphene, which is found naturally from camphor laurel, a large evergreen tree found in Asia. It is a compound that is often used in fragrances, cooking, medicine, and religious practices. Camphor has a high demand, due to its rare occurrence in nature, but it was one of the first naturally occurring compounds to be synthesized in the lab. The experiment includes carbocation rearrangement and other reactions learned in chemistry 210 and 215. verall synthetic reaction scheme: Acetic Acid 95 o C Camphene C 2-1, 2 Cr Chromium Trioxide S Sulfuric acid Camphor

2 Step 1 Synthetic transformation 1: Conversion of Camphene to Experimental 1: The rearrangement and acetoxylation of camphene resulted in the formation of isobornyl acetate. To perform the reaction, 5.5 mmols of camphene was placed into an acetic acid solution (5.5mmol in water, in a flask over heat). Aliquots were taken at consistent time intervals to track the progress of the reaction. After completion, the flask was cooled and placed into a water bath. A separation funnel was used to remove the aqueous layer. A drying agent (magnesium sulfate) was added to the organic layer and filtered out. The solvent of the organic layer was then dried using a rotavapor to retrieve the product. Expected yield: 96.5 mol % 0.723g Safety, disposal and green issues 1: Camphene is highly flammable, so it should not be used near an open flame. It should be disposed of in the correct waste bottle. Also, acetic acid is corrosive and will cause burns, so it must be used accordingly. It must be disposed of in the aqueous acid waste bottle.

3 Step 2: Conversion of to -1, 2 Experimental 2: The treatment of Isobornyl acetate began with the addition of 2.5 ml of Na to the Isobornyl Acetate recovered in aqueous solution, 75% ethanol, 25% water, in a hydrolysis reaction. The solution was gently heated with reflux condensation for 60 min. After allowing the system to cool to room temperature, the isoborneol precipitated out of solution, and dried via vacuum filtration. The resulting product was eluted in a thin layer chromatography setup with 3 parts ethyl acetate and two parts n-hexane, run with Camphene. Expected Yield: ~100%.568g. Safety, disposal and green issues 2: This process had little biological repercussions. It was conducted in an aqueous environment under strongly basic conditions, so contact with the skin should be avoided. is a stable compound but is highly flammable, and will sublimate if not kept in a cool, covered environment. The compound is harmful if swallowed, and is a respiratory, skin and eye irritant. Isobornyl acetate should be protected from heat and light because it will readily ignite. The byproducts of this reaction are all aqueous products, which are relatively harmless and are quite easily disposed.

4 Step 2: xidation of to Camphor Experimental 3: First, Jones reagent was prepared. 25g of chromium trioxide was added to 25mL of concentrated sulfuric acid. In a separate Erlenmeyer flask, isoborneol was dissolved in acetone. ver the course of 10 minutes, 1mL of Jones reagent was added dropwise to the isoborneol solution with swirling, in an ice bath. After the mixture was removed from the ice bath, it was allowed to warm to room temperature. Vacuum filter to retrieve the precipitate and dry. Expected Yield: ~100%.560g. Safety, disposal and green issues 2: The Jones reagent should be slowly added because the oxidation reaction is very exothermic. Jones reagent is very toxic, thus gloves and goggles should be worn at all times. Step 3 should be done in the hood to minimize the inhaling of chemicals. The Jones reagent should be disposed of properly.

5 verall budget: Chemical Supplier Cost Amt. Needed Total Camphene Aldrich $53.40/100g.75 g. $0.40 Chromium(VI) Sigma Aldrich $42.20/25g 1.00 g $1.68 oxide Glacial Acetic Sigma Aldrich $37.00/1 kg.315 g $0.01 Acid (537020) Sulfuric Acid Sigma Aldrich $47.50/2.5L 1.00 ml $0.02 (435589) Magnesium Sulfate Sigma-Aldrich $87.30/kg 2g $0.18 References: Total costs per synthesis: $2.39 1) Da Silva, K. A.; Kozhenikov, I. V.; Gusevskaya, E. V. Journal of Molecular Catalysis A: Chemical. 2003, 192, ) Da Silva, K. A.; Kozhenikov, I. V.; Gusevskaya, E. V. Journal of Molecular Catalysis A: Chemical. 2003, 192, Nimitz, J. S. Experiments in rganic Chemistry: From Microscale to Macroscale, 1 st Ed. New Jersey: Prentice all, ) Krishnaswamy, N. R. Resonance. 1996, 1, Markgraf, J.. Journal of Chemical Education. 1967, 44,