Asymmetric synthesis of cis-7-methoxycalamenene via the intramolecular Buchner reaction of an α-diazoketone

J Org Chem. 2012 Feb 17;77(4):2035-40. doi: 10.1021/jo202499j. Epub 2012 Feb 7.

Abstract

The asymmetric synthesis of cis-7-methoxycalamenene 1 has been accomplished using the intramolecular Buchner reaction of α-diazoketone 7 as the key step in the synthetic route. Upon reduction of the equilibrating azulenone structure 8, the resulting azulenol 9 rearranges to dihydronaphthalene 10 containing the 6,6-membered bicyclic ring system characteristic of 1, by means of an acid-catalyzed aromatization process. Transformation of 10 to 1 is accomplished through a three-step reaction sequence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Azulenes / chemistry*
  • Catalysis
  • Cyclization
  • Ketones / chemistry*
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Naphthalenes / chemistry*
  • Sesquiterpenes / chemical synthesis*
  • Spectrophotometry, Infrared
  • Stereoisomerism
  • Terpenes / chemical synthesis*

Substances

  • Azulenes
  • Ketones
  • Naphthalenes
  • Sesquiterpenes
  • Terpenes
  • cis-7-methoxycalamenene