Polygonapholine: A Total Synthesis Questions the Identity for the Purported Structure of the Natural Product

J Org Chem. 2022 Nov 18;87(22):15713-15718. doi: 10.1021/acs.joc.2c02339. Epub 2022 Nov 9.

Abstract

Polygonapholine was isolated in 1997 from the Polygonatum alte-lobatum rhizome. Based on spectroscopic data, it was assigned a structure comprising an unusual cis-2,6-disubstituted bis-aryl morpholine ring to which is attached a (Z)-4-hydroxycinnamate as an amide and an (E)-4-hydroxycinnamate as an ester. Being a meso compound, polygonapholine should not exhibit an optical rotation as reported. A total synthesis of the purported morpholine alkaloid presented herein reveals discrepancies between the synthetic and the natural product casting doubt on the originally proposed structure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids*
  • Biological Products*
  • Molecular Structure
  • Morpholines
  • Rhizome / chemistry
  • Spectrum Analysis

Substances

  • Biological Products
  • Alkaloids
  • Morpholines