Structural Elucidation and Total Synthesis of Three 9-Norlignans from Curculigo capitulata

J Org Chem. 2019 May 3;84(9):5195-5202. doi: 10.1021/acs.joc.9b00170. Epub 2019 Mar 29.

Abstract

Capitulactones A-C, three unprecedented 9-norlignans featuring a unique 3,5-dihydrofuro[2,3- d]oxepin-7(2 H)-one scaffold, were isolated from the roots of Curculigo capitulata. Their structures with absolute configurations were unambiguously established by a combination of spectroscopic data, ECD analysis, and total synthesis. Biomimetic total syntheses of three pairs of the corresponding enantiomers were achieved in 9-10 steps with overall yields of 14.8, 12.7, and 10.3%, respectively. Notably, the unique scaffold of the common western hemisphere of the molecules was constructed by using the oxidation-reduction strategy from benzodihydrofuran.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chemistry Techniques, Synthetic
  • Curculigo / chemistry*
  • Lignans / chemical synthesis*
  • Lignans / chemistry*
  • Models, Molecular
  • Molecular Conformation
  • Oxidation-Reduction
  • Stereoisomerism

Substances

  • Lignans