Catalyst-controlled formal [4 + 3] cycloaddition applied to the total synthesis of (+)-barekoxide and (-)-barekol

J Am Chem Soc. 2010 Sep 8;132(35):12422-5. doi: 10.1021/ja103916t.

Abstract

The tandem cyclopropanation/Cope rearrangement between bicyclic dienes and siloxyvinyldiazoacetate, catalyzed by the dirhodium catalyst Rh(2)(R-PTAD)(4), effectively accomplishes enantiodivergent [4 + 3] cycloadditions. The reaction proceeds by a cyclopropanation followed by a Cope rearrangement of the resulting divinylcyclopropane. This methodology was applied to the synthesis of (+)-barekoxide (1) and (-)-barekol (2).

Publication types

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

MeSH terms

  • Catalysis
  • Cyclization
  • Diterpenes / chemical synthesis*
  • Diterpenes / chemistry
  • Molecular Conformation
  • Organometallic Compounds / chemistry*
  • Rhodium / chemistry*
  • Stereoisomerism

Substances

  • Diterpenes
  • Organometallic Compounds
  • barekol
  • Rhodium