Enantioselective total synthesis of a potent antitumor antibiotic, fredericamycin A

J Am Chem Soc. 2001 Apr 11;123(14):3214-22. doi: 10.1021/ja0035699.

Abstract

The asymmetric total synthesis of both enantiomers of the potent antitumor antibiotic fredericamycin A (1) is detailed based on the protocol for the construction of its peri-hydroxy polyaromatic skeleton bearing the chirality at the spiro carbon via a strong base-induced cycloaddition of suitably substituted homophthalic anhydrides (AB-ring unit) with an optically active CDEF-ring unit. Particular attention has been given to the novel synthesis of the optically active spiro carbon center by a stereospecific rearrangement of optically active benzofuzed-trans-epoxy acylates leading to spirocyclopentane-1,1'-indane systems. This method is quite useful for the construction of an optically active spiro compound and was applied to the synthesis of the optically pure CDEF-ring unit of 1. Cycloaddition of the optically pure CDEF-ring unit to AB-ring units prepared via benzyne afforded two natural and unnatural-type hexacyclic compounds, which were converted to natural and unnatural enantiomers of synthetic 1, and the absolute configuration of natural 1 was determined as S.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibiotics, Antineoplastic / chemical synthesis*
  • Circular Dichroism
  • Crystallography, X-Ray
  • Isoquinolines / chemical synthesis*
  • Molecular Structure
  • Spiro Compounds / chemical synthesis*
  • Stereoisomerism

Substances

  • Antibiotics, Antineoplastic
  • Isoquinolines
  • Spiro Compounds
  • fredericamycin A