Synthesis and Odor of Chiral Partial Structures of Khusimone. Part 2

Abstract

Dedicated with best personal wishes to Prof. Dr. W. Fleischhucker on the occasion of his 65th birthday (16.1X.96) Khusimone (l), one of the main odor-donating compounds of vetiver oil is subject of the following study on structure/odor relationship. The omittance of the ethano bridge of the tricyclic khusimone leads to a bicyclic system. The stereoselective approach to this degraded structure is described, and the olfactory properties are studied. The key step of the synthesis of the hydrindane nucleus is based on a highly diastereoselective conjugate addition to a chiral 0x0-cyclopentene-2-carboxylate.

Odds and Trends: Recent Developments in the Chemistry of Odorants

“…[ (153) [88] as well as on their chiral partial structures [89,90] showed, however, that neither bvetivone (153) nor the partial structures possess the pleasant vetiver scent. [92] seco-Khusimone (À)-161 could not be evaluated since epimerization favored the corresponding trans-fused 3aS,8aR isomer. [88] Therefore, khusimone (À)-159 seems to be the only compound of vetiver oil which perfumers agree possesses a typical vetiver odor.…”

Volatile constituents of vetiver: a review

“…The previous work of Kido and Yoshikoshi, which had previously described 64 as a synthetic product, was a great help to this study, especially to define its stereochemistry. With its complex structure and its important role in the odour of vetiver, 64 has stimulated many studies directed toward its total synthesis . The structure and relative stereochemistry of 64 is now well established.…”

“…With its complex structure and its important role in the odour of vetiver, 64 has stimulated many studies directed toward its total synthesis. [43,122,[132][133][134][135][136][137][138][139] The structure and relative stereochemistry of 64 is now well established. Nevertheless, wrong structures of VEO constituents can still be found in the recent literature, even for this well described ketone.…”

Allerlei Trends: die neuesten Entwicklungen in der Riechstoffchemie

“…Schema [87] neben 2-Acetyl-4a-methyl-8-methylenoctalin 156, das einen intensiven holzig-ambraartigen Geruch aufweisen soll, und dem Nordihydro-b-vetivon 157 mit seinem intensiven, reichen, holzig-pfeffrigen Geruchsprofil. [92] Das seco-Khusimon (À)-161 konnte geruchlich nicht ausgewertet werden, da eine Epimerisierung das entsprechende transverknüpfte (3aS,8aR)-Isomer begünstigte. Neuere Arbeiten von Spreitzer et al zu (À)-und ()-b-Vetivon 153 [88] sowie deren chiralen Partialstrukturen [89,90] ergaben hingegen, dass weder b-Vetivon 153 noch die Partialstrukturen einen angenehmen Vetivergeruch aufweisen.…”