1. CHEM 430 – Structural Analysis of Organic Compounds Spring 2014

3. Introduction Our approach must differ depending on the type of work we are performing. 1.“Cold” analysis – the unknown organic is a complete unknown Forensic chemistry EPA methods and related analyses Natural products taxonomy In these cases, little if anything is known about the individual compounds – detective work must recreate the entire structure 2.Results of a synthetic experiment In this case, the majority of the structure should be maintained, the goal is to analyze for and confirm changes 3.Characterization for the chemical literature – Assignments! The analysis here is to confirm the author’s findings and serve as a benchmark for further work on the compound

4. Introduction All approaches will involve a general flow of information:

5. Methods in General Use

6. NMR Spectroscopy

10. Mass Spectrometry

11. Vibrational Spectroscopy

12. Electronic Absorption Spectroscopy

13. Limitations (and grades) We can only see what our ‘shutter speed’ allows: TechniqueTimescale X-ray diffraction10 -18 UV10 -15 Visible10 -14 IR10 -13 ESR10 -4 to -8 NMR10 -1 to -9 Mössbauer10 -7 Experimental separation of isomers10 2

14. Limitations (and grades) Can we ever achieve a fully secure structure (or why did I get it wrong?)? Harrisonin Heterocycles 1976, 5, 485. J. Nat. Prod. 1997, 60, 822

15. Limitations (and grades) Can we ever achieve a fully secure structure (or why did I get it wrong?)? J. Am. Chem. Soc. 1983, 105, 6312. Tetrahedron Lett. 1992, 33, 3711 J. Antibiotics 1986, 39, 1527

16. Limitations (and grades) Can we ever achieve a fully secure structure (or why did I get it wrong?)? J. Org. Chem. 2001, 66, 8717. Tetrahedron Lett. 2003, 44, 1203

17. Limitations (and grades) Can we ever achieve a fully secure structure (or why did I get it wrong?)? J. Nat. Prod. 2000, 63, 1677. J. Nat. Prod. 2003, 66, 716

18. Limitations (and grades) Can we ever achieve a fully secure structure (or why did I get it wrong?)? J. Am. Chem. Soc. 2003, 125, 5296. Org. Lett. 2004, 6, 2607 Spirastrellolide

19. Limitations (and grades) Can we ever achieve a fully secure structure (or why did I get it wrong?)? J. Nat. Prod. 2007, 70, 412. J. Am. Chem. Soc. 2008, 130, 804 (+)-Neopeltolide

20. Welcome to CHEM 430 Assumptions: Working knowledge of general and organic chemistry You have seen basic IR and NMR before Math skills permit solution of algebra and trigonometric problems and a rudimentary understanding of simple calculus