Enantioselective total synthesis and confirmation of the absolute and relative stereochemistry of streptorubin B

J Am Chem Soc. 2011 Feb 16;133(6):1799-804. doi: 10.1021/ja109165f. Epub 2010 Dec 17.

Abstract

The enantioselective total synthesis of the pyrrolophane natural product streptorubin B is described. Key steps in the concise route include the application of a one-pot enantioselective aldol cyclization/Wittig reaction and an anionic oxy-Cope rearrangement to forge the crucial 10-membered ring. Comparisons between CD spectra of synthetic and natural samples of streptorubin B coupled with X-ray crystallography allowed for the determination of the absolute stereochemistry of this natural product for the first time. These studies also provided unambiguous proof of the relative configuration between the butyl side chain and the bispyrrole subunit. Additional studies revealed a novel atropstereoselective Paal-Knorr pyrrole condensation and provided fundamental experimental insight into the barrier for atropisomerization of the natural product.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Products / chemical synthesis*
  • Biological Products / chemistry*
  • Chemistry Techniques, Synthetic / methods*
  • Prodigiosin / analogs & derivatives*
  • Prodigiosin / chemical synthesis
  • Prodigiosin / chemistry
  • Stereoisomerism
  • Substrate Specificity

Substances

  • Biological Products
  • streptorubin B
  • Prodigiosin