Trans-methyl cinnamate

The same authors also reported the dispersion of palladium nanoparticles in a water/AOT/n-hexane microemulsion by hydrogen gas reduction of PdClJ and its efficiency for hydrogenation of alkenes in organic solvents [79]. UV-visible spectroscopy and TEM analysis revealed the formation of Pd nanoparticles with diameters in the range of 4 to 10 nm. Three olefins (1-phenyl-l-cyclohexene, methyl trans-cinnamate, and trans-stilbene) were used as substrates for the catalytic hydrogenation experiments under 1 atm of H2 (Table 9.12). All of the Start-... 

Remarkably, the use of a fluorous biphasic solvent system in combination with a [Rh(NBD)(DPPE)]+-type catalyst (NBD = norbornadiene) copolymerized into a porous nonfluorous ethylene dimethacrylate polymer, resulted in an increased activity of the catalyst relative to a situation when only toluene was used as solvent [30]. The results were explained by assuming that fluorophobicity of the substrate (methyl-trans-cinnamate) leads to a relatively higher local substrate concentration inside the cavities of the polymer when the fluorous solvent is used. That is, the polymer could be viewed as a better solvent than the fluorous solvent system. This interpretation was supported by the observations that (i) the increase in activity correlates linearly with the volume fraction of fluorous solvent (PFMCH) and (ii) the porous ethylene dimethacrylate polymer by itself lowers the concentration of decane in PFMCH from 75 mM to 50 mM, corresponding to a 600 mM local concentration of decane in the polymer. Gas to liquid mass transport limitation of dihydrogen could be mled out as a possible cause. 

The versatility of TOT in clathrate formation is further illustrated by the discovery of several other clathrate types belonging to various space groups PT (/raw-stilbene, cw-stilbene a-bromobutyric acid benzene ) Pl(PT) (methyl tran -cinnamate, methyl cw-cinnamate) P2 (weso-2,3-butanediol carbonate) P2j/c (weTO-2,3-di-bromobutane) C2jc (3-bromooctane ethyl a-bromobuty-rate ° ) Pbca (l,l,l-trifluoro-2-chloro-2-bromoethane) Pbcn (dl-2,3-dibromobu-tane) hexagonal R (a-chlorotetrahydropyran) The clathrates for which X-ray crystal structure determinations have been completed are indicated in Table 1. 

The addition of benzonitrile oxide to acrylic acid gave only the 4-carboxylic acid (441) (59MI41601), while addition to cis- and trans-cinnamic esters gave cis and trans diastereomeric pairs of 4-carboxylic acids (442) (Scheme 100) (59MI41600). Arbisono repeated the experiment and, when methyl c/s-cinnamate was used, in addition to the 4-carboxylic acid some 5-carboxylic acid (442) was isolated (66MI41600). The reaction of vinyl bromides with benzonitrile oxide yielded only an isoxazole and not a bromoisoxazoline (Scheme 101) (78JCR(S)192). 

Figure 10.7 The phase diagram (a) and the glass transition temperatures (b) of a PSC/PVME mixture obtained, respectively, by light scattering and differential scanning calorimetry (DSC). Irradiation experiments were performed in the miscible region at 127 C indicated by (X) in the figure of trans-cinnamic acid-labeled polystyrene/poly(vinyl methyl ether) blends.

Ethyl-4-hydroxy-2-methyl-3(2H)-furanone Ethyl trans-cinnamate... 

Whereas palladium(0)-catalyzed reactions of dialkyl fumarate and dialkyl maleate yield reaction products identical to those obtained from the phosphane-modified nickel-catalyzed reactions (vide supra), analogous palladium(0)-catalyzed reactions with ( )-but-2-enoic or (E)-cinnamic acid derivatives lead to different products to the nickel-catalyzed reactions, i.e. in the palladium-catalyzed reactions formal distal cleavage of but-2-enoic MCP occurs to provide methyl tra i-2-methyl-4-methylenecyclopentanecarboxylate (12, R = Me) and methyl trans-4-methylene-2-phenylcyclopentanecarboxylate (12, R = Ph), respectively." Yields and stereoselectivities are slightly higher with palladium(O) catalysts. When R = Me, 7.4% of the C-C double bond isomerization product, methyl traM -2,4-dimethylcyclopent-3-enecarboxylate (13, R = Me), is additionally obtained, raising the combined yield of cyclocodimers to 49.9%. With methyl (jE )-cinnamate, analogous isomerization only occurs upon workup, i.e. distillation of the crude product. 

Benzoic and salicylic acids. Two of the simplest plant acids arising from trans-cinnamate are benzoic acid, accumulated in plums and cranberries, and salicylic acid, present in all green plants and accumulated as methyl esters or glycosides in some plants, e.g., those of the willow family. Salicylic acid is made by hydroxylation of benzoic acid, which can be formed from trans-cinnamate by P oxidation as depicted in Fig. 25-8, but it may also arise from isochoris-mate as shown in Fig. 25-2. Salicylic acid plays a central role in resistance of plants to a variety of... 

Lee and Kim used a lipase catalyzed transesterification to resolve racemic syn-l,2-diols of trans cinnamate 7.6.12. Both enantiomers of the resolved compounds 7.6.13 and 7.6.14 were then converted to side chain methyl ester 7.6.19 in good yield (290). One route proceeded from diol monoacetate 7.6.13 through the tosylate 7.6.15 to the epoxide 7.6.16 and thence to the azide 7.6.17. The second route converted the diol 7.6.14 to the bromoacetate 7.6.18 and thence to the azide 7.6.17. Conversion of 7.6.17 to the final product 7.6.19 by standard methods completed the synthesis. 

As one of the enzymic reactions, asymmetric synthesis catalyzed by cyclodextrins has been studied in the past, but gave all the products in a low optical yield. We have already found a strong chiral induction for the chlorination of methacrylic acid in the crystalline cyclodextrin complexes. 100 % enantiomeric excess (e.e.) of (-)-2,3-dichloro-2-methyl-propionic acid and 88 % e.e. of its enantiomer were isolated in a- and 3-cyclodextrins, respectively. This paper describes asymmetric addition of gaseous halogens and hydrogen halides in the crystalline complexes comprising trans-cinnamic acid as a reactant and a- or 3-cyclodextrin as chiral matrix. Asymmetric bromination of menthyl cinnamate and of salts from the acid and several chiral amines have been reported, but gave low chiral inductions up to 2 16 % e.e.. 

Fig. 13.7 Compounds present in male Grapholitha molesta hairpencils ethyl-tran -cinnamate (I), (-)-mellein (II), methyl-jasmonate (III), and methyl 2-epijasmonate (IV) (Baker eta/., 1981b).

C10H9NO5, Methyl 4 hydroxy-3-nitro-trans-cinnamate, 41B, 135 C10H10O4, Methyl 3 (3,4-dihydroxyphenyl)-2-propenoate, 45B, 87 CioHioO , 2,5-Diacetylhydroquinone, 44B, 97... 

To a solution of m-ethyl cinnamate (44, 352 mg, 85% pure, 1.70 mmol) and 4-phenylpyridine-A-oxide (85.5 mg, 29 mol%) in 1,2-dichloromethane (4.0 mL) was added catalyst 12 (38.0 mg, 3.5 mol%). The resulting brown solution was cooled to 4°C and then combined with 4.0 mL (8.9 mmol) of pre-cooled bleach solution. The two-phase mixture was stirred for 12 h at 4°C. The reaction mixture was diluted with methyl-t-butyl ether (40 mL) and the organic phase separated, washed with water (2 x 40 mL), brine (40 mL), and then dried over Na2S04. The drying agent was removed by filtration the mother liquors concentrated under reduce pressure. The resulting residue was purified by flash chromatography (silica gel, pet ether/ether = 87 13 v/v) to afford a fraction enriched in cis-epoxide (45, cis/trans . 96 4, 215 mg) and a fraction enriched in trans-epoxide cis/trans 13 87, 54 mg). The combined yield of pure epoxides was 83%. ee of the cis-epoxide was determined to be 92% and the trans-epoxide to be 65%. 

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