Putative Biomimetic Route to 8-Oxabicyclo[3.2.1]octane Motif from a Humulene Sesquiterpenoid Zerumbone

Org Lett. 2020 Aug 21;22(16):6409-6413. doi: 10.1021/acs.orglett.0c02220. Epub 2020 Aug 7.

Abstract

An approach to expand the diversity of terpenes to novel polycyclic skeletons with contiguous stereogenic centers is described. An unprecedented 8-oxabicyclo[3.2.1]octane motif was obtained in quantitative yield by photoirradiation of zerumbone in the presence of a catalytic amount of Lewis acid. The vital role of light in the isomerization of double bonds in zerumbone, which ensued cyclization via tertiary carbocation intermediate, emulates a biosynthetic route. Synthetic diversification of the phototransformed product afforded epoxy derivatives with up to seven contiguous stereogenic centers and eight-member ring fused tricyclic motifs. The present work sheds light on the possible role of UV irradiation in the biosynthesis of oxo-bridged tricyclic structures from polyene terpenes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomimetics
  • Cyclization
  • Molecular Structure
  • Monocyclic Sesquiterpenes / chemistry*
  • Sesquiterpenes / chemistry*
  • Terpenes / chemistry*
  • Terpenes / isolation & purification

Substances

  • Monocyclic Sesquiterpenes
  • Sesquiterpenes
  • Terpenes
  • zerumbone
  • humulene