The Jubilee of Methyl Jasmonate and Hedione^®

Abstract

An internal historical point of view is presented on the discovery and development of both methyl jasmonate and its saturated analogue Hedione®. A discussion of the synthetic approaches performed during the last decade, and structureactivity relationships of analogous structures are also presented.

Efficient synthesis of the cyclopentanone fragrances (Z)-3-(2-oxopropyl)-2-(pent-2-en-1-yl)cyclopentanone and Magnolione®

“…It is worthy of note that the stereogenic centers at C -2 of 3 and 4 were partially epimerized under the very mild Lewis acidic conditions, which is in agreement with the observations made by the other groups that the cis -isomer readily epimerizes to the trans -isomer under thermal, mild Lewis-acidic or basic conditions. 1 …”

“…1 In addition to being an expensive flavor ingredient, 1 has also been identified as a plant hormone that regulates diverse developmental processes (such as seed germination, root growth, fertility, fruit ripening, and senescence) and defense responses (activating plant defense mechanisms in response to insect-driven wounding, various pathogens, and environmental stresses). 2 Moreover, the anticancer activity of 1 was also reported.…”

“…Currently, 2 is a highly prized fragrance ingredient for the manufacture of high grade perfumes and also finds utility in fruit flavors, tea, tobacco, and laundry products. 1,4 …”

“…In particular, compared to methyl dihydrojasmonate ( 2 ), compound 4 is less biodegradable and exhibits a greater odor strength, and a more floral, intense jasminic note. 6 Magnolione has been commercialized by Givaudan , 1 and is used as a precious ingredient in several perfumes (such as ‘Coriandre’ ( Couturier , 1973; 13%), ‘Eden’ ( Cacharel , 1994; 0.7%)) and thus has attracted considerable attention from the synthetic community. 7 …”

“…It is interesting to note that for 1 , 2 and 4 , only the 2 S ,3 R -isomers are found to possess very intense, true floral fragrance. 1 For example, 2 S ,3 R - 4 exhibits the most intense floral, jasmine-like odor of Magnolione, with a threshold concentration of 0.29 ng/L, while the other isomers of 4 only display a very weak jasmine note. 7d In this regard, selective syntheses of Magnolione and other jasmonoids with enriched 2 S ,3 R -isomer content is a highly desirable endeavor of interest for the fragrance industry.…”