Of methyl jasmonate

Allyl aryl ethers are used for allylation under basic conditionsfh], but they can be cleaved under neutral conditions. Formation of the five-membered ring compound 284 based on the cyclization of 283 has been applied to the syntheses of methyl jasmonate (285)[15], and sarkomycin[169]. The trisannulation reagent 286 for steroid synthesis undergoes Pd-catalyzed cyclization and aldol condensation to afford CD rings 287 of steroids with a functionalized 18-methyl group 170]. The 3-vinylcyclopentanonecarboxylate 289, formed from 288, is useful for the synthesis of 18-hydroxyestrone (290)[I7I]. 

When the cyclic enone is unsubstituted, but the resulting enolate is quenched with an electrophile under conditions of kinetic control the irons adduct is formed exclusively303. Particularly successful is the sequential Michael addition/enolate alkylation in diastereoselective routes to frans-a,/j-difunctionalized cycloalkanones and lactones304-308. The key steps in the synthesis of methyl ( + )-jasmonate (3)309-310 (syn/anti diastereoselection) and (-)-khushimone (4) (syn/anti and induced diastereoselection) illustrate this sequence311 (see also Section D. 1.1.1.3.). 

Inomata100 utilized a tandem retro-Diels-Alder-ene reaction for an enantioselective total synthesis of (+)-methyl jasmonate (Scheme 41). The TMS group on the alkene was essential to the efficiency of the reaction, by producing a higher energy level of the HOMO for the ene reaction. 

Wang, D. M., K. Kubota and A. Kobayashi. Optical isomers of methyl jasmonate in tea aroma. Biosci Biotech Biochem 1996 60(3) 508-510. Kitagawa, I., S. Kobayashi, H. Sage-saka and T. Uemura. Extraction of saponins from tea leaves. Patent-Japan Kokai Tokkyo Koho-07 61,998 1995 9 pp. 

Dihydro-1,3-oxazines have served both as nucleophilic and electrophilic agents in the preparation of carbonyl compounds. The multiple uses of this heterocycle are nicely revealed in the synthesis of methyl jasmonate (739) (73JOC175). 

Dehydrogenation of an allyl 0-ketocarboxylate is a key step in a synthesis of methyl jasmonate that has been reported.362... 

Michael addition.1 This ketene silyl acetal undergoes Michael addition to a,fl-enones in acetonitrile in the absence of a Lewis acid to afford the corresponding O-silylated Michael adduct in high yield. These O-silyl enolates undergo site-specific electrophilic substitution. This sequence was used for vicinal dialkylation of cyclohexanone (equation I) and of cyclopentanone. It is particularly useful for synthesis of methyl jasmonate and related compounds from cyclopentenone. 

A significant contribution was made to the science of plant cell culture production of paditaxel. Methyl jasmonate solutions that had been pipetted into cell suspension cultures caused transient increases in paditaxel production [27]. This was the first report of modeling that indicated ethylene and methyl jasmonate may participate in cross-talk signal transduction in plants. Other papers have subsequently appeared which demonstrate enhancement of paditaxel productivity by the application of methyl jasmonate to several Taxus species [87,88]. 

The interdependence of methyl jasmonate with chitin- and chitosan-derived elicitors was studied using plant cell suspension cultures of Taxus canadensis. Induction of the biosynthesis of paditaxel and other taxanes was enhanced when methyl jasmonate and elicitors were added 8 days after culture transfer compared to treatments in which only methyl jasmonate or only elicitor was added. The optimal elicitor concentration using AT-acetylchitohexaose was 0.450 pM, but only in the presence of methyl jasmonate. Little, if any, induction of taxane formation occurred with the oligosaccharide alone. The optimal methyl jasmonate concentration was 200 pM using colloidal chitin or oligosaccharides of chitin and chitosan as elicitors. 

Elicitors evoke responses in whole plants by a variety of routes. Touch produces dramatic responses to a number of plants such as Mimosa, and systemic responses to an elicitation encounter on one part of a plant become expressed on distal plant parts within a short period of time. Elicitation events on one plant in a chamber which cause the biosynthesis of methyl jasmonate (MJ) as a primary response to the elicitation and a secondary response as a effect of the methyl jasmonate have been shown to produce the secondary response on other plants in the chamber that are not elicited. The volatility of methyl jasmonate is... 

Sisido, K. Kurozumi, S. Utimoto, K. J. Org. Chem. 1969, 34, 2661. [Biichi, G. and Egger, B. (J. Org. Chem. 1971, 36, 2021) obtained a high yield (93.5%) of methyl jasmonate in the hydrogenation using Lindlar catalyst in petroleum ether as solvent, compared to 60% yield obtained by Sisido et al. in methanol, although on a much larger scale],... 

OL, -Bifunctionalization of cyclopentenone.1 Although simple ester enolates do not undergo conjugate additions, the enolate of 1 undergoes conjugate addition to cyclopentenone in THF/HMPT (3.3 1) at -20°. This reaction coupled with in situ enolate alkylation provides a notably short synthesis of methyl jasmonate (3). 

Michael additions. Gerlach and Kiinzler report that the lithium enolate of S-t-butyl thioacetate undergoes 1,4-addition to cyclopentenone. They have extended this Michael reaction to a synthesis of methyl jasmonate (5), based on the similar conjugate addition of the trimethylsilyl enolate 1 promoted by tetra-n-butylam-monium fluoride. The adduct 2 was alkylated by l-bromo-2-pentyne in the presence of tetra-n-butylammonium fluoride to give 3 in rather low yield. Remaining steps to 5 were methanolysis and partial hydrogenation of the triple bond. 

Spiroalkylation of cyclopentanone, Naf and Decorzant have reported a novel reaction between cyclopentanone and l,4-dibromo-2-pentene (1) resulting in the spiro[2.4]heptene-4-ones 2. NaH or NaNHj can be used as base (THF, 65°), but yields are higher using phase-transfer conditions Aliquat 336, aqueous KOH, 65° yield of 2a and 2b, 40-55%. Descotes et al. had previously reported that 2a rearranged to 3 when heated, but his yield for the preparation of 2 from cyclopentanone was only about 7.5%. Methods for preparation of methyl jasmonate (4) from 3 and for preparation of (Z)-jasmone (5) from 3 had already been developed. 

Synthesis of methyl jasmonate (8). Meyers and Nazarenko have reported a synthesis of methyl jasmonate (8), a constituent of the characteri.stic odor of jasmine,... 

One typical example is given by the asymmetric synthesis of (-)-methyl jasmonate (Scheme 43). ... 

Conjugate addition to enones. In the presence of l equivalent of TiCl4,1 undergoes 1,4-addition to cycloalkenones. An example is formulated for a recent synthesis of methyl jasmonate (2) in equation (1). 

A certain activity of methyl jasmonate at about 8 ppm concentration for the acceleration of ripening in apples and degreening in oranges, dne to stimnlation of ethylene biosynthese, has been reported (Olias et al. 1990). However, these results seems to be inconsistent at least in orange (Artes et al. 1994, 2000). 

OLiAS JM, SANZ LC, RIOS JJ and PEREZ AG. 1990. Characterization of methyl jasmonate effects on storage life and frait quality of apples. XXll Intern Horticultural Cong. Paper 3330. 

Scheme 5.43 illustrates three applications of this methodology to total synthesis. The first exeunple is taken from Posner s synthesis of estrone and estradiol [211], the second from Posner s synthesis of methyl jasmonate [212], and the third from Holton s synthesis of aphidicolin [213]. The latter is particularly noteworthy in that two contiguous quaternary centers are created in the asymmetric addition with excellent selectivity. In the estrone synthesis, the chirality sense of the product is consistent with the nonchelate model, but the other two examples adhere to a chelate model. Note that the difference is the degree of substitution at the a-position of the enolate. 

The 3R configuration is important for high activity. All natural molecules have the 3R absolute configuration. In the case of methyl jasmonate, the 3S enantiomer is far less active than the natural molecule, with the racemate having an intermediate effectiveness... 

Kim, H.-J., Chen, R, Wang, X., and Choi, J.-H. Effect of methyl jasmonate on phenolic, isothiocyanate, enzymes in radish sprout (Raphanus sativus L.). J. Agric. Pood Chem. 54, 7263-7269, 2006. 

Ketchnm, R.E., Rithner, C.D., Qin, D., Kim, Y.S., WiUiams, R.M., and Croteau, R.B. Taxus metabolomics methyl jasmonate preferentially induces production of taxoids oxygenated at C-13 in Taxus media cell cultures. Phytochemistry 62, 901-909, 2003. Kim, H.-J., Fonseca, J.M., Choi, J.-H., and Kuhota, C. Effect of methyl jasmonate on phenolic compounds and carotenoids of romaine lettuce (Lactuca sativa L.). 7. Agric. Food Chem. 55, 10366-10372, 2007. 

Wang, S.Y, and Zheng, W. Preharvest application of methyl jasmonate increases fruit quality and antioxidant capacity in raspberries. Int. J. Food Sci. Technol. 40, 187-195, 2005. 

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