Total synthesis of a keramamide

Abstract

The first total synthesis of a molecule possessing the structure proposed for keramamide J is described, providing data indicating that the structure of this natural product should be re-examined.

References

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15. Authentic samples of KJ and KF are not available. We thank Professor Kobayashi for providing a copy of the ¹H NMR spectrum for natural KJ..
16. Chemical degradation of KG converts the homo-Ile fragment to D-isoleucine indicating that KG possesses the (R) configuration at both C-13 and C-15..
17. A peak corresponding to L-alanine was also detected in this analysis, indicating that this residue did not epimerize during the cyclization reaction..