simple lab assignment

timer Asked: Nov 20th, 2018
account_balance_wallet $5

Question description

simple assignment including what i learnt from the lab and abstract as indicated in the outline.

You may find this helpful Outline • Abstract: • Introduction: • Materials • Procedure: • Data and Results • Discussion • Reason for the lab • What I learnt from the lab • Conclusion reference EPOXIDATION OBJECTIVES: To perform an epoxidation reaction and synthesize a strawberry-flavored compound. To purify the compound using chromatography and analyze it with NMR TIME ALLOCATED: TWO LAB PERIODS Background With more substitution, as in compound 1, E and Z isomers can potentially result. However, in the reaction shown, the geometry of the starting material determines the product stereochemistry because the mechanism is stereoselective. The oxygen atom is delivered to one side of the alkene at the same time as the double bond is being broken. An epoxide is a cyclic ether with a three-member ring structure. Due to the strain in the ring, epoxides are quite reactive. A common procedure for the synthesis of epoxides is a reaction involving an alkene as a starting material and a peroxiacid. The reaction shown below is an example in which a disubstituted alkene reacts with a common peroxyacid, m-chloroperoxybenzoic acid (mCPBA), to form an epoxide and 3-chlorobenzoic acid. /\ Experimental Week 1. Set up of the epoxidation reaction 12 34 Because substituents on a three-membered ring can be either pseudo-axial or pseudo-equatorial, 1,2- disubstituted oxacyclopropanes can have cis or trans stereochemistry. 1. Into a clean, dry vial, weigh 176 mg (1.0 mmol) of ethyl trans cinnamate. 2. Add 4 mL of dichloromethane. On weighing paper, weigh out 670 mg mCPBA. Note: the mCPBA is not pure, the commercial material is 77% by weight and you will need to take that into account in your yield calculations. 3. Add the mCPBA to the vial, cap the vial and shake until the mCPBA completely dissolves. 4. Vent the vial by briefly removing the cap. Label the vial with the reagent structures, date, and your initials and then seal it with parafilm. Give it to your instructor to place in the refrigerator. Week 2. TLC, Column Chromatography, and NMR spectroscopy 1. Gravity-filter the solution into your separatory funnel and rinse the solid with 3 mL of CH2CI2. 2. Add 8-10 mL of aqueous 10% aqueous sodium sulfite (Na2SO3) and shake the funnel. 3. Drain out the bottom organic layer into a small beaker, then drain off the aqueous layer. Add the organic layer back to the separatory funnel, and then wash with 8-10 mL of 5% aqueous sodium bicarbonate, NaHCO3, to remove any remaining acid. 4. Collect the bottom layer and dry it over CaCb. Transfer the dry organic solution to a 50 mL round bottom flask (the one in your drawer, not the yellow kit) and remove most of the CH2CI2 using a rotary evaporator or alternative method. Column chromatography 1. Set up a 6-inch alumina column using 25% ethyl acetate in hexanes as eluting solvent 2. Load the concentrated sample using a pipet and rinse the flask with 0.5 mL of eluting solvent to rinse the round-bottomed flask, then add it to the column. 3. Collect five fractions (-5 mL each fraction) from the column, and analyze them using TLC. TLC analysis • Your product will be fairly dilute, so spot each fraction about 4x (put spots on top of each other) • Spot the starting ester on the same plate using 25% ethyl acetate in hexanes as eluent. • Use anisaldehyde stain to visualize the spots (in the hood, immerse the dry TLC plate in the anisaldehyde solution, wipe off excess stain, and heat on a hotplate until pink - • Tare a round-bottom flask, and then combine the fractions containing only the green spot. Remove ALL of the solvent by rotovap. Weigh your flask and calculate the % yield. NMR analysis • Prepare an NMR sample of the epoxide product 3 in CDCb using one drop of the dry product in a clean NMR tube and adding CDCb as described in the NMR instructions. The spectrum should be analyzed 13C NMR Real life example Researchers at Glaxo-SmithKline recently reported an innovative synthesis of 1,2 amino alcohols (important intermediates in the synthesis of oncological drugs). This approach is particularly suitable for industrial applications that use large scale synthesis. The reported approach utilizes an epoxide. McIntyre, J. P.; Beachy, T. M.; Thamattoor, D. M. J. Chem. Educ., 2002, 79, 96-98. 1 1 Complete the worksheet Complete the writing assignment “Full paper1 2' Reference 1) Lim, J.; Leitch, D. C.; Org. Process Res. Dev. 2018,22, 641-649 2) 2) Pageau, G. J.; Mabaera, R.; Kosuda, K. M.; Sebelius, T. A.; Ghaffari, A. H.; Kearns, K. A.;

Tutor Answer

School: UC Berkeley

flag Report DMCA

Goes above and beyond expectations !

Similar Questions
Hot Questions
Related Tags

Brown University

1271 Tutors

California Institute of Technology

2131 Tutors

Carnegie Mellon University

982 Tutors

Columbia University

1256 Tutors

Dartmouth University

2113 Tutors

Emory University

2279 Tutors

Harvard University

599 Tutors

Massachusetts Institute of Technology

2319 Tutors

New York University

1645 Tutors

Notre Dam University

1911 Tutors

Oklahoma University

2122 Tutors

Pennsylvania State University

932 Tutors

Princeton University

1211 Tutors

Stanford University

983 Tutors

University of California

1282 Tutors

Oxford University

123 Tutors

Yale University

2325 Tutors