Synthesis of Kuehneromycin B and Panudial from Kuehneromycin A

Abstract

Syntheses of kuehneromycin B and panudial are presented starting from kuehneromycin A using a thermal decarboxylation under pH control.

Key words

total synthesis - terpenoids - natural products - hydrolysis - decarboxylation

References

• 2 Erkel G. Lorenzen K. Anke T. Velten R. Gimenez A. Steglich W. Z. Naturforsch. C: Biosci.  1995,  50:  1 
• 3 Jauch J. Angew. Chem. Int. Ed.  2000,  39:  2764 ; Angew. Chem. 2000, 112, 2874
• 4 Lorenzen K. Anke T. Anders U. Hindermayr H. Hansske F. Z. Naturforsch. C: Biosci.  1994,  49:  132 
• 5 Jauch J. Wallner C. Herdtweck E. Eur. J. Org. Chem.  2003,  3060 
• 6 See e.g.: March J. Advanced Organic Chemistry   4th ed.:  Wiley; New York: 1992.  p.629 ; and literature cited therein
• 7 See e.g.: March J. Advanced Organic Chemistry   4th ed.:  Wiley; New York: 1992.  p.631 
• 10 CRC Handbook of Chemistry and Physics   82nd ed.:  Chapman & Hall/CRC; New York: 2001. 

1

New address: Universität des Saarlandes, Organische Chemie, Postfach 15 11 50, 66041 Saarbrücken, Germany. E-mail: [e-mail].

8

Under the assumption of thermodynamic control DFT calculations (B3LYP/6-31G*) led to ΔΔG(6a/10-epi-6a) of ca. 8 kcal/mol. Thus, the equilibrium constant is ca. 10⁶ in favor of 6a.

9

Unfortunately, the compounds have been mislabeled in the CD spectra shown in Figure [2] a. In the text of ref. [2] the data of the CD spectra have been listed correctly.