Rapid conversion of spirostans into furostan skeletons at room temperature

Steroids. 2012 Jan;77(1-2):59-66. doi: 10.1016/j.steroids.2011.10.004. Epub 2011 Oct 20.

Abstract

We report a facile protocol to obtain 22-substituted furostans and pseudosapogenins in high yields from (25R)- and (25S)-sapogenins. This method involves the treatment of the sapogenin with acetic-trifluoroacetic mixed anhydride and BF(3)·OEt(2) at room temperature, followed by the addition of a nucleophile (H(2)O, MeOH or KSeCN). In the case of 22-hydroxyfurostans, they can be transformed to pseudosapogenins by treatment with p-toluensulfonic acid.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetic Anhydrides
  • Antineoplastic Agents, Phytogenic / analysis
  • Antineoplastic Agents, Phytogenic / chemical synthesis*
  • Benzenesulfonates / chemistry
  • Boranes / chemistry
  • Chemistry, Pharmaceutical*
  • Cyanides / chemistry
  • Fluoroacetates
  • Magnetic Resonance Spectroscopy
  • Methanol / chemistry
  • Molecular Structure
  • Sapogenins / analysis
  • Sapogenins / chemical synthesis*
  • Spirostans / analysis
  • Spirostans / chemistry*
  • Stereoisomerism
  • Temperature
  • Trifluoroacetic Acid / chemistry
  • Water / chemistry

Substances

  • Acetic Anhydrides
  • Antineoplastic Agents, Phytogenic
  • Benzenesulfonates
  • Boranes
  • Cyanides
  • Fluoroacetates
  • Sapogenins
  • Spirostans
  • Water
  • boron trifluoride etherate
  • trifluoroacetic anhydride
  • Trifluoroacetic Acid
  • 4-toluenesulfonic acid
  • Methanol