1. Total Synthesis of (+)-Biotin Hoffmann-La Roche J. Am. Chem. Soc. 1982, 104, 6460-6462. Presented by Derek Ahneman

2. Hoffmann-La Roche, Inc. Swiss global health care company Founded by Fritz Hoffmann-La Roche in 1896 Headquartered in Basel, Switzerland Enrico Baggiolini’s group located in Nutley, NJ Roche in FY 2011: Revenue: $47 billion Profit: $10 billion Over 80,000 employees

3. Biotin Essential water soluble vitamin (B 7 ) Coenzyme in the synthesis of fatty acids, isoleucine, and valine Also plays a role in gluconeogenesis, or generation of glucose from non- carbohydrate sources (lactate, etc.) Produced by intestinal bacteria Tetrahydrothiophene ring with cyclic urea Three contiguous stereocenters

4. Retrosynthetic Analysis of Biotin

5. Synthesis of (+)-Biotin

7. Conclusion Total synthesis of (+)-biotin is reported Relatively simple and inexpensive starting materials Key step is an intramolecular nitrone-olefin [3+2] cycloaddition reaction Diastereoselectivity controlled by conformation of ten-membered ring …Questions?