A Novel Access to Ionone-Type Compounds: (E)-4-oxo-β-ionone and (E)Oxo-β-irone via metal-catalyzed intramolecular reactions of α-diazo ketones with furans

✍ Scribed by Ernest Wenkert; René Decorzant; Ferdinand Näf

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: German
• Weight: 693 KB
• Volume: 72
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19890720416

✦ Synopsis

Dedicated to Dr. G. Ohlogon the occasion of his 65th birthday (5.IV. 89) (E)-5-Demethyl-4-oxo-~-ionone (2), (E)-4-oxo-p-ionone (3), (E)-.l-oxo-p-irone (4), and the five-membered ring analogs 36-41 were synthesized by a novel, convergent route starting from 2-methylfuran (1). A recently discovered, intramolecular reaction of 2-(diazoacyl)furans, catalyzed by dirhodium tetraacetate, leading to dienediones served as key step, thereby testing its utility in natural-product synthesis for the first time.

Introduction.

~ As part of a broad study of reactions of a -diazocarbonyl compounds with enol derivatives by one of the authors [ 11, there was recently developed a route for a general access to dienediones by the interaction of furans with metal carbenoids, generated by Rh,(OAc),-catalyzed decomposition of a -diazoacyl derivatives (Scheme l a ) [2].