Question

Fall 2017 Organic Chemistry Laboratory CHEM.2290 Experiment S: SN2 substitution: Synthesis of Virstatin ethyl ester CALCULATION THIS EXPERIMENT REQUIRES BALANCED CHEMICAL EQUATIONS AND THEORETICAL YIELD IN THE PRE- AND POST-LABS (hint: the equation below is not balanced) K CO, DMF REQUIRED READING Technique 7.6: Drying tubes, page 73 Technique 25: Infrared spectroscopy, page 307. Skip sections 25.1-25.8 (pages 308-320) Technique 11: Removing insoluble impurities, page 124-125 RECOMMENDED KLEIN READING Chapter 7: Substitution reactions, page 287 INTRODUCTION Cholera is a terrible disease, endemic in much of Africa, and the cause of many millions of deaths in historic times. It is a water-borne disease, the result of poor sanitation and sanitary practices. Eating food and drinking water infected with the gram-negative bacterium Vibrio cholera is the primary means of transmission. No other common disease kills as quickly. Upon infection, death can occur in as little as three hours in severe cases. More commonly, from the onset of exhaustive diarrhea to shock can take to 12 hours, with death in 18 hours to several days when untreated. Loss of fluids can be at the rate of one liter per hour The most effective treatment for cholera is by oral rehydration to replace the loss of water and electrolytes; antibiotics merely shorten the course of the disease. Cholera can be prevented by municipal water treatment and the construction of proper water supplies, and so is no longer a health threat in fully developed countries A major problem with modern antibiotics is the development of mutations in the bacteria being treated that confers resistance to their action. The most notorious is methicillin resistant Staphylococcus aureus (MRSA). Staph bacteria developed resistance to penicillin in 1947, just four years after it was introduced. It is very common in hospitals, and staph is now resistant to a broad spectrum of antibiotics. Platensimycin is one of the antibiotics produced by Streptomyces platensis, and it blocks fatty acid biosynthesis which gram-positive bacteria need to synthesize their cell membrane. It has been shown effective against MRSA in mice. Cholera has developed a similar resistance to antibiotics, so another avenue for stopping the reproduction of the bacterium was explored. Virstatin is not an antibiotic; it is a small molecule inhibitor. It does not kill the V. cholera bacterium, but instead decreases its virulence. It inhibits the genes that promote colonies of the bacteria to form and that produce the toxin causing debilitating diarrhea. Thus, it can prevent extensive colonization of V. 18 P age

Answer 1

Balanteal egn 0 tu.ざ odut cuven shekli at -3200 to 3300 ul mass 147I lmol 0,00126 moles oith Keautant eicld Theorical yul i