Methyl Dihydrojasmonate

Methyl dihydrojasmonate is a fragrance ingredient with a jasmine-like odor, used in many fragrance mixtures[1].
Liquid|Pale straw-coloured to yellowish oily liquid; Powerful floral, jasmine-like aroma
Methyl dihydrojasmonate has a powerful sweet-floral, jasminelike, somewhat fruity odor. This is the odoriferous component in jasmine oil (Jasminum gradiflorum L.). May be prepared by condensation of 2-pentyl-2-cyclopenten-l-one with ethyl malonate, followed by hydrolysis, decarboxylation, and methylation.
Methyl dihydrojasmonate is a jasmine fragrance that is closely related to methyl jasmonate, which occurs in jasmine oil. Methyl dihydrojasmonate has been identified in tea. It is a liquid with a typical fruity, jasmine-like blossom odor.Methyl dihydrojasmonate is prepared by Michael addition of malonic acid esters to 2-pentyl-2-cyclopenten-l-one, followed by hydrolysis and decarboxylation of the resulting (2-pentyl-3-oxocyclopentyl)malonate, and esterification of the (2-pentyl-3-oxocyclopentyl)acetic acid [304]. 2-Pentyl-2-cyclopenten-1-one is prepared by an aldol condensation between cyclopentanone and valeraldehyde and subsequent isomerization of the resulting 2- pentylidenecyclopentanone or by palladium catalyzed decarboxylation of allyl 2-oxo-1-pentylcyclopentanecarboxylates.Dealkoxycarbonylation of the malonate can also be accomplished directly with water at elevated temperature.Methyl dihydrojasmonate of the aforementioned quality consists of a 9 : 1 equilibrium mixture of the trans- and cis-isomers. However, methyl cisdihydrojasmonate is the much more intensive isomer, with a threshold about 20 times lower than that of the trans-isomer. Therefore, methyl dihydrojasmonate qualities with enriched portions of the cis-isomer are also marketed.These “high-cis” products are colorless liquids with extremely powerful jasmine character.Thedifferent commercial qualities may contain different amounts of the cis-isomer.High-cis methyl dihydrojasmonate is a valuable material in fine fragrances but suffers from stability problems due to its tendency to isomerize into the equilibrium mixture and, therefore, has only limited usage in other perfumery applications.High-cis methyl dihydrojasmonate can be produced from the equilibrium mixture by special distillation techniques in which isomerization is effected by the action of sodium carbonate. A high proportion of cis methyl dihydrojasmonate can also be obtained by hydrogenation of methyl dehydrodihydrojasmonate, which is accessible from 1(2-furyl)-hexanol via rearrangement, isomerization, etherification, and condensation with dimethyl malonate.For other stereoselective synthetic approaches, see review.Of all possible isomers, the (+)-(1R)-cis-isomer possesses the most characteristic and intensive jasmine odor.Therefore, an industrially feasible process for the production of a methyl dihydrojasmonate with a high portion of this isomer has been developed. The process comprises the catalytic hydrogenation of the corresponding cyclopenteneacetic acid in the presence of a ruthenium(II) complexwith chiral ligands and subsequent esterification.Methyl dihydrojasmonate is used in perfumery for blossom fragrances, particularly in jasmine types.
Methyl dihydrojasmonate is a fragrance ingredient mainly used in the perfumes, fragrance formulations, personal care and cosmetic products. It occurs naturally in pine honey and rhododendron honey.