Concise synthesis of anti-HIV-1 active (+)-inophyllum B and (+)-calanolide A by application of (-)-quinine-catalyzed intramolecular oxo-Michael addition

J Org Chem. 2004 Apr 16;69(8):2760-7. doi: 10.1021/jo035753t.

Abstract

(-)-Quinine-catalyzed intramolecular oxo-Michael addition (IMA) of 7-hydroxy-5-methoxy-8-tigloylcoumarins was developed for the enantioselective construction of 2,3-dimethyl-4-chromanone systems in the context of the asymmetric synthesis of anti-HIV-1 active Calophyllum coumarins. Combination of the IMA and MgI(2)-assisted demethylation of the 5-methoxy group along with isomerization of the formed chromanone systems as key steps successfully led to the concise synthesis of (+)-inophyllum B and (+)-calanolide A, possible candidates for AIDS drugs. Further examination of the asymmetric IMA with cinchona alkaloids lacking a methoxy group on the quinoline skeleton suggested the influence of the methoxy substituent on stereoselectivity at the stereogenic centers of the chromanone systems.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-HIV Agents / chemical synthesis*
  • Catalysis
  • Coumarins / chemical synthesis*
  • Molecular Structure
  • Pyranocoumarins
  • Quinine / chemistry*
  • Stereoisomerism

Substances

  • Anti-HIV Agents
  • Coumarins
  • Pyranocoumarins
  • inophyllum B
  • Quinine
  • calanolide A