Struktur und Geruch, XIII. Synthese und olfaktorische Eigenschaften von Megastigmatrienon-Analoga

✍ Scribed by Weyerstahl, Peter ;Meisel, Thomas ;Mewes, Klaus ;Negahdari, Shoreh

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 808 KB
• Volume: 1991
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.199119910104

✦ Synopsis

Structure–Odor Correlation, XIII^1)^. – Synthesis and Olfactive Properties of Megastigmatrienone Analogues

The key compound 9 was readily prepared in larger quantities by an improvement of a known procedure. Addition of carbanions to the unprotected ketone 9 gives the hydroxy ketones 16–21 via the acetals 10–15. Dehydration of 16–20 furnishes the dienones 2–6 while 7 is available in fair yield via the acetoacetate 21. Through intramolecular cyclization also the ester 26 is formed which affords with NaOH the keto ester 29 by a retro‐Michael reaction. The diketone 28 (obtained from 29) can be reduced selectively to give 30, dehydration of which leads to 31/32. – The odor of 2 (camphor, sweet, wood, plum) is the olfactive link between the odor of isophorone and megastigmatrienone (A). Elongation of the alkyl group (→ 3–5) leads first to a herbaceous, then to a leathery note. The one‐diene‐one 7 smells unexpectedly weak. For the very strong odor (tobacco, wood, plum) of A obviously the total osmophor is responsible including the unsaturated side chain.