Example 1
Adding 10g of methyl dehydrojasmonate (Compound 1) to a reaction vessel containing 0.05g of 5wt% Pt/C and 10ml of methanol, substituting with nitrogen three times, charging 1MPa of hydrogen, stirring at 50 ℃ until the reaction of the raw materials is completed, and stopping the reaction. To obtain a reaction solution containing methyl 3-hydroxy-2-pentyl-cyclopentenylacetate (compound 2).
And (3) reducing the reaction temperature of the reaction liquid to 10 ℃, adjusting the hydrogen pressure to 2MPa, stirring until the raw materials are reacted, and stopping the reaction. Filtering with celite pad, adding saturated sodium bicarbonate into the filtrate, extracting, rectifying under reduced pressure, and separating to obtain colorless oily cis-3-hydroxy-2-pentyl-cyclopentyl methyl acetate (compound 3) with yield of 95%. H-NMR (400MHz, CDCl3): 0.89 (t, J =7.0,3H); 1.12-1.20 (m, 1H); 1.22-1.38 (m, 7H); 1.47-1.58 (m, 1H); 1.77-1.83 (m, 2H); 1.91-1.98 (m, 1H); 2.02-2.10 (m, 2H); 2.14 (dd, J =10.0,14.6,1H); 2.38 (dd, J =6.2,14.6,1H); 2.58-2.67 (m, 1H); 3.67 (s, 3H); 3.99 (dt, J =4.4,6.8,1H).
8.0g of cis-3-hydroxy-2-pentyl-cyclopentylacetic acid methyl ester (compound 3) was dissolved in 10ml of dichloromethane, 0.1wt% of cesium carbonate was added, the mixture was opened to the atmosphere, the mixture was stirred at 25 ℃ until the reaction was completed, and the reaction was stopped after completion of the reaction of the starting materials was detected. Extraction and reduced pressure distillation are carried out, thus obtaining the cis-methyl dihydrojasmonate (compound 4) of colorless oil, the yield is 90 percent, and the cis-isomer content is 92 percent. H-NMR (400MHz, CDCl3): 0.89 (t, J =7.0Hz, 3H); 1.54-1.11 (m, 6H); 1.58 (m, 1H); 1.86 (m, 1H); 2.27-2.07 (m, 5H); 2.30 (q, J =7.2hz, 1h); 2.42 (dd, J =5.4,15.6hz, 1h); 2.82 (m, 1H); 3.66 (s, 3H).

Patent Citations (8)

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 Method for preparing methyl dihydrojasmonate  CN CN101519355B 胡雨来 西北师范大学
Priority 2009-03-17 • Filed 2009-03-17 • Granted 2011-11-30 • Published 2011-11-30
 
Abstract
The invention provides a method for synthesizing methyl dihydrojasmonate. 2-pentyl cyclopentenone is adopted as a raw material; the raw material and allyl zinc bromide are subjected to 1,4-Michael addition to form 2-pentyl-3-allyl cyclopentanone; the 2-pentyl-3-allyl cyclopentanone is oxidized by sodium periodate in the presence of a ruthenium trichloride hexahydrate catalyst to synthesize dihydrojasmonic acid; and then the dihydrojasmonic acid is esterified to form the methyl dihydrojasmonate. The raw material of the method is cheap and low in cost; the process is simple and convenient in operation; the reaction conditions are mild and easy to control; the synthesis route is short and the synthesis period is reduced greatly; and the reaction product is single, high in yield (up to 65 to 85 percent), less in environmental pollution, and environmentally-friendly.


Embodiment
The present invention is described further below by concrete enforcement.
Step 1: the preparation of 2-amyl cyclopentenone
The 2-amyl cyclopentenone can be bought from the market, also can get by following prepared:
With NaOH (0.83g), H 2O (75ml) adds there-necked flask, is heated to 25 ℃ with water-bath, drips cyclopentanone (38g) from dropping funnel, keeps temperature of reaction to be no more than 32 ℃ during dropping, drips valeraldehyde (22g) after adding again, keeps reacting liquid temperature to be no more than 32 ℃.Add the back at 28 ℃ of reaction 1h, add acetate (1.5g) and stir 2min, tell organic layer, once with the saturated common salt washing.
Add NaHSO 4Solution at room temperature stirs 20min, adds a small amount of propyl carbinol.Tell organic layer, wash once with saturated common salt aqueous solution.Organic layer is put into round-bottomed flask, add the HBr (6.5ml) of propyl carbinol (132ml) and 40%, behind the reflux 1.5h,, pour separating funnel into, use saturated NaCl, NaHCO successively the reaction solution cooling 3, the NaCl solution washing, the anhydrous MgSO of organic layer 4Dry.With water pump pressure reducing and steaming propyl carbinol, use the oil pump underpressure distillation again.Collect 130 ℃～140 ℃, the cut of 0.085MPa gets colourless liquid, is the 2-amyl cyclopentenone.Productive rate 65%.Its reaction formula is as follows:
Figure G2009100218015D00031
The spectral data of product characterizes as follows:
IR(KBr)v maxcm -1：2926，2858，1704，1633；
1HNMR(400MHz，CDCl 3)：δ＝0.83-0.90(m，3H)，1.25-2.58(m，12H)，7.29-7.31(m，1H)；
13CNMR(100Hz，CDCl 3)：δ＝210.1，157.3，146.5，34.5，31.5，27.4，26.4，22.4，13.9。

Step 2: the preparation of 2-amyl group-3-allyl group cyclopentanone
(1) preparation of allyl group bromination zincon
Allyl group bromination zincon can be bought from the market, also can get by following prepared:
In exsiccant two neck bottles (50ml), put into zinc powder (0.021mol),, add tetrahydrofuran (THF) (THF) (3ml) with 1 with the air in the nitrogen replacement bottle, 2-ethylene dibromide (4～5), the reaction mixture heating up to there being bubble to produce, is naturally cooled to room temperature, add trimethylchlorosilane (Me 3SiCl) (4～5), stirring at room 15min adds allyl bromide 98 (0.020mol) and tetrahydrofuran (THF) (THF) (10ml) then, and stirring reaction is standby.Its reaction formula is as follows:
Figure G2009100218015D00041
(2) under nitrogen protection, in another 100ml three-necked bottle, put into acetylacetonate nickel (Ni (acac) 2) (0.0012mol), triethylamine (Et 3N) or triphenyl phosphorus (Ph 3P) (0.0048mol), tetrahydrofuran (THF) (THF) (10ml) is heated to reaction mixture 60 ℃, and stirring reaction 10min is cooled to room temperature, slowly adds the allyl group bromination zincon of above-mentioned preparation, after adding reaction mixture is chilled to-15 ℃ with the cryosel bath.From dropping funnel, drip 2-amyl cyclopentenone (0.010mol), trimethylchlorosilane (Me then 3SiCl) (0.018mol) and the mixture (5ml) formed of tetrahydrofuran (THF) (THF).Add the back and continue stirring reaction, allow cryosel bathe nature and be warming up to room temperature, coreaction 12 hours.The 5mol/L HCl that in reaction flask, adds 10ml then, restir reaction 1 hour.Add the 10ml ether, organic phase is told in extraction.Use anhydrous magnesium sulfate drying, residuum carried out column chromatography after boiling off solvent, colourless or light yellow liquid, be 2-amyl group-3-allyl group cyclopentanone.Productive rate 73%.Its reaction formula is as follows:
The spectral data of product characterizes as follows:
IR(KBr)v maxcm -1：2927，2858，1740，1641；
1HNMR(400MHz，CDCl 3)：δ＝0.87(t，J＝7.0Hz，3H)，1.26-2.43(m，16H)，5.05-5.10(m，1H)，5.77-5.79(m，1H)，5.81-5.88(m，1H)；
13CNMR(100Hz，CDCl 3)：δ＝221.1，135.8，116.6，54.2，41.1，38.6，37.7，32.1，28.0，26.5，26.4，22.4，14.0。

Step 3: the preparation of Dihydrojasmone acid
In the 50ml round-bottomed flask, add 0.388g 2-amyl group-3-allyl group cyclopentenone, add 7ml water and 7ml acetonitrile again, add the 1g sodium periodate then, stir, add the 0.02g hydrate ruthenium trichloride again, the temperature of solution rises to 30 ℃ gradually, keep temperature of charge under 12 ℃～20 ℃, slowly add the 3.5g sodium periodate, reactant was stirred 2 hours down at 17 ℃, added the ethyl acetate stirring reaction then 1 hour, filter, filtrate is used saturated Na then with 0.1mol/L salt acid elution 2S 2O 3Solution washing is used ethyl acetate extraction, collected organic layer, and solvent evaporated gets yellow pasty state liquid, and column chromatography gets colourless liquid, is Dihydrojasmone acid.Productive rate 92%.Its reaction formula is as follows:
Figure G2009100218015D00051
The production spectra diagram data characterizes as follows:
IR(KBr)v maxcm -1：2924，2854，1739，1710，1459；
1HNMR(400MHz，CDCl 3)：δ＝0.88(t，J＝7.2Hz，3H)，1.23-2.68(m，16H)，11.18(s，1H)；
13CNMR(100Hz，CDCl 3)：δ＝219.6，178.1，54.1，38.7，37.7，37.6，32.0，27.7，27.1，26.2，22.4，14.0。

Step 4: the preparation of methyl dihydrojasmonate
0.55g methyl dihydrojasmonate and anhydrous methanol (20ml) are joined in the three-necked bottle, slowly drip thionyl chloride (SOCl down at 0～-15 ℃ 2) (1.5ml), stirring reaction recession in 1 hour deicing salt bath at room temperature continues to stir after 3～5 hours, boils off anhydrous methanol on Rotary Evaporators, obtains the target product methyl dihydrojasmonate.Productive rate 84%, its reaction formula is as follows:
The production spectra diagram data is as follows:
IR(KBr)v maxcm -1：2955，2930，2859，1739，1437，1166；
1HNMR(400MHz，CDCl 3)：δ＝0.87(t，J＝7.0Hz，3H)，1.22-2.65(m，16H)，3.71(s，1H)；
13CNMR(100Hz，CDCl 3)：δ＝
219.7，172.6，54.1，51.6，38.9，38.0，37.7，32.0，27.8，27.2，26.3，22.4，14.0。
Use other catalyzer, lewis acidic embodiment same as the previously described embodiments.





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Bio-based methyl dihydrojasmonate, bio-based cyclopentanone, preparation method …
WO CN CN118871415A 阎震 法国特种经营公司
Priority 2022-01-31 • Filed 2023-01-31 • Published 2024-10-29  (Rhodia patent)

 
The invention relates to biobased methyl dihydrojasmonate, biobased cyclopentanone, a preparation method and application thereof.
Background
Methyl dihydrojasmonate (CAS 24851-98-7) is an aromatic compound, the odor of which is floral and citrus when in the form of a racemic mixture. The compounds are used in the perfume industry and the food industry. Methyl dihydrojasmonate is used as a synthetic equivalent of methyl jasmonate, a component of naturally occurring jasmine. Industrially, methyl dihydrojasmonate can be prepared from adipic acid as a precursor for the preparation of cyclopentanone. Cyclopentanone can then be functionalized by aldol condensation with valeraldehyde followed by michael addition of dimethyl malonate.
Synthetic flavors are less preferred by consumers than natural-derived flavors. Thus, there is increasing interest in other sources of methyl dihydrojasmonate, and in particular in ways that use natural raw materials that can be marked as natural or biological in accordance with existing regulations.

Examples
Example 1: preparation of biobased cyclopentanone
3G of biobased furfuryl alcohol (100% biobased carbon content) was hydrogenated in 60mL of water in the presence of a nickel catalyst (30 mg). The hydrogen pressure was 30 bar and the temperature was 160 ℃.
After stirring for 3-4 hours, the reaction mixture was analyzed. Biobased cyclopentanone was obtained and showed a biobased carbon content of 100%. The conversion rate is 100%.

Example 2: preparation of methyl biobased dihydrojasmonate.
The biobased cyclopentanone of example 1 (100% biobased carbon content) was reacted with valeraldehyde to produce the compound of formula (III).

The compound of formula (III) is then reacted with 100% dimethyl biobased malonate having a 100% biobased carbon content.
Methyl dihydrojasmonate was obtained and showed a biobased carbon content of 62%.

Patent Citations (9)

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   CH382731A   1960-02-25  1964-10-15  Firmenich & Cie   Process for the preparation of alicyclic keto esters  
starting patent for methyldihydrojasmonate FR

  US3158644A  *  1960-02-25  1964-11-24  Firmenich & Cie  Alicyclic ketoesters and process for their manufacture



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aldol condensation cyclo +valeraldehyde
info here






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US-3978108-A    Cis methyl dihydrojasmonate     S.A. Des Etablissements Roure-Bertrand Fils & Justin Dupont    1970-12-23         
Cis methyl dihydrojasmonate
Abstract
Methyl dihydrojasmonate containing a major proportion of cis methyl dihydrojasmonate. The NMR spectrum of cis methyl dihydrojasmonate is illustrated in the attached drawings.Cis methyl dihydrojasmonate displays olfactory properties superior to those of the trans isomer making it very useful as an odoriferous agent. In order to prepare methyl dihydrojasmonate containing a major proportion and preferably at least 90% of cis isomer, methyl (2-pentyl-3-keto-cyclopenten-1-yl)-acetate is catalytically hydrogenated in the presence of an aluminium derivative                                                                                                                                                                                                                                                                                                                                                                                                                                                 The preparation of methyl dihydrojasmonate, the chemical name of which is methyl (2-pentyl-3-keto-cyclopentyl)-acetate, is described in as well as in French Pat. No. 1,280,432    U.S. Pat. No. 3,158,644. While methyl dihydrojasmonate is capable of existing in both the trans and cis forms, and is so generally indicated, for instance, in said U.S. patent, the face is that the cis form has not heretofore been isolated nor characterized. Furthermore, the process disclosed in said patents, production of either 100% of the trans isomer or possibly a very small percentage at best of the cis isomer intermingled with the essentially overwhelming content of the trans isomer, the latter constituting no less than about 95% by weight, perhaps more, of the methyl dihydrojasmonate. These two forms can be represented, in accordance with the usual conventions, by formulae I and II respectively. ##SPC1##

A process has now been found which enables the production of methyl dihydrojasmonate containing a major proportion, that is, more than 50% by weight, of the cis isomer. The process of this invention has proved to be capable of giving a methyl dihydrojasmonate containing upwards of 90% of the cis isomer.
It has furthermore surprisingly been found that cis methyl dihydrojasmonate and also methyl dihydrojasmonate containing a major proportion of the cis isomer is distinguished from the earlier trans product both by its olfactory characteristics and in that the physicochemical properties of the cis isomer differ from those of the trans isomer.       
                                                                                                                                                                                                                                                                 

Patent Citations (4)

   US4260830A 1980-01-18 1981-04-07 International Flavors & Fragrances Inc. Process for the preparation of methyl dihydrojasmonate and lower alkyl homologues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      full details here                                                                                                                                                                                                                           
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