Methyl dihydrojasmonate

Description

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.

Chemical properties

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.

Chemical properties

Methyl dihydrojasmonate has a powerful sweet-floral, jasmine-like, somewhat fruity odor. This compound is the odoriferous component of jasmine oil (Jasminum gradiflorum L.)

Occurrence

Reported found in jasmine oil (Jasminum gradiflorum L.) and black tea

The Uses of Methyl dihydrojasmonate

Methyl (3-Oxo-2-pentylcyclopentyl)acetate is used in the preparation of hydrogels as delivery systems for the slow release of bioactive carbonyl derivatives.

Preparation

By condensation of 2-pentyl-2-cyclopenten-1-one with ethyl malonate, followed by hydrolysis, decarboxylation and methylation

Taste threshold values

Taste characteristics at 20 ppm: sweet, floral, citrus, fruity and berry with tutti-frutti undernotes.

General Description

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.

Flammability and Explosibility

Non flammable

Trade name

Claigeon®, Cepionate®(Nippon Zeon),Hedione®,Hedione®HC (Firmenich), Kharismal® (IFF).