1. Lecture 17 Hand in Lecture Problem 6 The Synthetics Quiz 6 Review Reminder: Quiz 6 in lecture on Thursday & Hand in Selection Sheet! This Week in Lab: Finish Ch 9 Ch 7 Final Report Due Ch 12 Progress Check Next Week in Lab: Start synthetics! Synthetic #1 PreLab Due Ch 9 Final Report due the week of April 10th! Note: This week’s office hours are from 1 to 3 pm on Wednesday.

2. Natural Product Isolations Experiment 110: Cholesterol from Human Gallstones Extraction of cholesterol from gallstones using hot solvent Analyses: IR, NMR or MS Cholesterol: Attached to lipoproteins HDL and LDL Average human has 200 g of cholesterol located in spinal cord, brain, and nerve tissues May produce gallstones or cause hardening of the arteries

3. Natural Product Isolations Experiment 112: Isolation of Casein, Lactose & Albumin from Milk Casein: a phosphoprotein Albumin: a globular, water-soluble protein Lactose: a carbohydrate Techniques used to isolate these 3 biomolecules: Precipitation of casein Separation of lactose & albumin by centrifugation Analyses: Polarimetry of lactose

4. Natural Product Isolations Experiment 116: Soap from Nutmeg Isolate trimyristin from nutmeg Saponify trimyristin to form sodium myristate, a soap Saponification = hydrolysis of an ester Analyses: chemical tests and IR or NMR

5. Reduction Reactions Experiment 130: Hydrogenation of Olive Oil Reduction of C=C bonds Quick look at mechanism in class Analyses: IR & NMR

6. Reduction Reactions Experiment 135: Enzymatic Reduction: A Chiral Alcohol from a Ketone An asymmetric reaction! Quick look at a similar reduction mechanism in class Analyses: Polarimetry with IR or NMR

7. Substitution Reactions Experiment 142: Synthesis of a Plant Hormone S N 2 mechanism! Analyses: IR, NMR & MS 4-Chlorophenoxyacetic acid (2): Plant growth hormone Promotes growth of roots on plant clippings Prevents fruits from falling prematurely

8. Substitution Reactions Experiment 144: Synthesis of “OFF” Two-step process: 1. Make the acid chloride (mechanism not needed) 2. Make an amide from the acid chloride (acyl substitution reaction) Analyses: IR, NMR, or GC/GC-MS N,N-diethyl-m-toluamide (OFF): Insect repellent

9. Substitution Reactions Experiment 145: Synthesis of Norleucine S N 2 reaction - substitute Br with NH 2 Analysis: IR Norleucine: Not a naturally occurring amino acid Structural isomer of leucine and isoleucine (both essential AAs)

10. Substitution Reactions Experiment 146: Synthesis of Sulfanilamide Two substitution reactions plus a hydrolysis Analyses: Bioassay with IR or NMR Sulfanilamide: Inhibits growth of folic acid thus stopping the growth of bacteria

11. New PreLab Sections: Chromatographic & Spectral Features Comparisons For the synthetic experiments only! See Chapter 10 for details! Chromatographic Comparison Relative R f comparison between main organic starting material and main product of reaction. Example: Cyclohexanol would have a lower R f value due to the OH functionality, which is more polar than the alkene of cyclohexene. (Draw out structures)

12. PreLab Sections: Chromatographic & Spectral Features Comparisons For the synthetic experiments only! Spectral Features Comparison Consider diagnostic 1 H NMR & IR signals for the starting material and product that would be used to distinguish the two from one another. Example: (Draw out structures) CyclohexanolCyclohexene Diagnostic 1 H NMR Signals OH proton at 2-6 ppm, singlet =C-H (alkene) proton at 5-6.5 ppm, quartet or multiplet (due to complex splitting) Diagnostic IR SignalsO-H stretch (broad) at 3600-3200 cm -1 C=C stretch at 1658 cm - 1

13. Comments on Synthetics May need to repeat an experiment. Yields count! The quality of your technique will be evaluated. Check Chemical Inventory when looking for chemicals; check hooded shelf, common shelf, refrigerators, ask class/TA, or ask stockroom Get melting points for all solid products. Report yields for all products. Do TLC analysis for appropriate reactions. TLC charts posted throughout labs.

14. Troubleshooting No product formed: No reaction - recovered starting material; verify by TLC Check reagent bottles Check times and temperatures Check calculations Low yield after recrystallization: Added too much solvent? Concentrate solution. Obtain an oily-non-crystalline product? Try to recrystallize product to get a solid.

15. Quiz 6 Review Questions on: Basic theory of IR & NMR Data interpretation of IR & NMR data May include annotating data Solving unknown structures using data IR & NMR correlation charts will be provided. Look over old lecture problems and lab guide/McMurry problems.

16. Spectroscopy 1 H NMR: Determine bond connectivities/pieces of a structure, whole structure IR Use: Determine the functional groups present in a structure: -OH, C=O, C-O, NH 2, C=C, C  C, C=N, C  N NMR (Nuclear Magnetic Resonance Spectroscopy): Uses radio waves (electromagnetic radiation) Interacts with sample’s nuclei in the presence of a magnet Effect: nuclei flip and relax (known as resonance) IR (Infrared Spectroscopy) IR radiation Interacts with molecule as a whole Effect: bond vibrations within molecule

17. Quiz 6 Practice Problems Propose a structure that is consistent with the following data. C 4 H 7 BrO 2 1 H NMR:IR: 1.08 ppm (t, 3H)broad peak 2.07 ppm (m, 2H) 2500-3000 cm -1 4.23 ppm (t, 1H)peak at 1705 cm -1 10.97 ppm (s, 1H)

18. Quiz 6 Practice Problems C 7 H 8 O 1 H NMR:IR: 2.43 ppm (s, 1H)broad peak in 3200- 4.58 ppm (s, 2H) 3500 cm -1 region 7.28 ppm (m, 5H)