Cinnamic acid esters from

An example of the working curve approach, resulting from a study of the stereochemistry of the electrohydrodimerisation of cinnamic acid esters [38], is shown in Fig. 6.16. 

Phenylpropynoic acid (13) can be prepared from cinnamic acid esters by the addition of bromine to the double bond followed by dehy-drobromination with alcoholic potassium hydroxide (Scheme 5.14). 

This procedure illustrates a general method for the preparation of phenylcyclopropanes from cinnamic acids, esters, aldehydes, or alcohols. It complements the Simmons-Smith reaction as a general method for the preparation of such cyclopropanes. It offers advantages over the Simmons-Smith method in cases in... 

There is some evidence that y-oryzanol present in rice bran oil lowers semm total- and LDL cholesterol as well (16, 185, 188). Butter from the Shea tree, Butyro-spermum parkii, contains a very high level of 4,4-dimethylsterols (about 8%) mostly as esters of cinnamic acid (oryzanols). Apparent absorption of these sterols, as estimated by their disappearance from feces, was found to be 27-52% in Wistar rat and 13-49% in humans (189). It was found that the cinnamic acid esters of the 4-desmethylsterols of rice bran oils, but not those of the 4,4 -dimethylsterols of shea nut oil possess hypolipidemic activity (190). 

Homologues.—The homologues of benzyl alcohol result from substitution of the hydroxyl group in one of the methyl groups of xylene, mesitylene, etc., or, as in the examples previously given of secondary and tertiary aromatic alcohols, by the substitution of hydroxyl in a poly-carbon side chain either saturated or unsaturated. These need not be discussed further except to mention that both phenyl propanol, CeHs—CH2—CH2—CH2OH, and phenyl propenol, CeHs—CH = CH— CH2OH, are also found as cinnamic acid esters in storax. 

Electrolyses of substrates of the cinnamic acid ester family (Table 4) in anhydrous MeCN were shown to result in formation of 7-60% of the CHD [Eq. (3)], corresponding exclusively to the ( ) coupling as determined from the stereochemistry of the cyclopenta-none formed by hydrolytic decarboxylation [61]. The stereochemistry was later verified by x-ray crystallography [65]. The stereoselectivity in the coupling step was originally rationalized in terms of orientation of the substrate molecules at the electrode surface [61]. However, later kinetic studies have shown that dimerization of the radical anions is fairly slow (Table 3), and takes place in the diffusion layer at a distance from the electrode. 

Higher yields of the CHD were obtained in another series of the cinnamic acid esters (Table 4) upon reduction in DMF [68,69], and similar yields were obtained from substances with a Me, Et or Ph substituent at the )6-carbon in 12 [68]. 

For a series of cinnamic acid esters formed from chiral alcohols, reduction in DMF gave the CHD with from 0% de for the (—)-menthyl ester up to >95% de for the (—)-endo-hoxny ester [66] (Table 4). The menthyl and the bornyl cinnamates have virtually... 

Baizer and coworkers established the most brilliant industrial electroorganic synthesis of the hydrodimerization of acrylonitrile to adiponitrile. They extended this hydrodimerization to a variety of activated olefins and in some cases [41 3] paid attention to the stereochemistry of products. However, their stereochemical data were not enough to discuss the stereochemical course of the reaction. Afterward, an attempt was made to provide a working hypothesis in the hydrodimerization of cinnamates by considering an orientated adsorption of radical anion intermediates on a cathode surface, but this was not persuasive because of a lack of experimental data on the stereochemistry of both the starting olefins and products. Recently Utley and coworkers [44-46] have reported stereochemical data of hydrodimers derived from a variety of cinnamic acid esters with chiral alcohol components. 

Glycosides of this vitamin (sometimes denoted as vitamin B3) were not described, however, there exists an evidence that bound niacin from wheat bran (termed niac)4in) has a single nicotinic acid moiety at least partially linked to an aromatic amine with glucose, xylose, and arabinose in a 6 3 1 molar ratio per molecule, with approximately three cinnamic acid esters [152,177,178]. It seems that these glycosidic complexes limit the bioavailability of the nicotinamide and for its liberation they must be treated, e. g., by soaking com in a lime solution, traditionally performed in Central America during production of tortillas [179]. 

Main components During fermentation, vanillin (up to app. 2.5%) is formed from the odourless glucovanillin by enzymatic hydrolysis. Its aroma is rounded-off and modified by p-hydroxybenzoic acid, p-hydroxybenzaldehyde, p-hydroxybenzyl methyl ether, vanillyl alcohol, vanillic acid, cinnamic acid ester and various other trace constituents [291, 292], Also the resins, gums, amino acids and other organic acids contribute to the typical flavour of the cured beans [293[. For further constituents and characterisations of fruits from different growing areas see [294[. 

Table S. Phenyicyclopropanes from Cinnamic acids, Esters, and Aldehydes...

The preparation of chelating surface-active diphosphines proved to be more successful. The BDPP analogue R,R-(9) was synthesized by lithiation of tris[p-(3-phe-nylpropyl)phenyl]phosphine, reaction with (R,R)-2,4-pentane-diylditosylate and subsequent sulfonation with concentrated sulfuric acid [16]. Hydrogenation of the prochiral olefin (Z)-2-(N-acetamido)cinnamic acid ester in a two-phase system (ET0Ac/H20) with Rh complexes derived from R,R-(9) was accomplished with identical selectivity compared with the unsulfonated BDPP and improved reactivity compared with BDPPTS (2). 

One of the most important transformations catalysed by palladium is the Heck reaction. Oxidative addition of palladium(O) into an unsaturated halide (or tri-flate), followed by reaction with an alkene, leads to overall substitution of a vinylic (or allylic) hydrogen atom with the unsaturated group. For example, formation of cinnamic acid derivatives from aromatic halides and acrylic acid or acrylate esters is possible (1.209). Unsaturated iodides react faster than the corresponding bromides and do not require a phosphine ligand. With an aryl bromide, the ligand tri-o-tolylphosphine is effective (1.210). The addition of a metal halide or tetra-alkylammonium halide can promote the Heck reaction. Acceleration of the coupling can also be achieved in the presence of silver(I) or thallium(I) salts, or by using electron-rich phosphines such as tri-tert-butylphosphine. ... 

The name beyerane stems from the Australian plant Beyeria leschenaultii, which contains (+)-17-0-cinnamoyl-15-beyerene-3,17,19-triol, also referred to as the cinnamic acid ester of beyerol. (+)-15-Beyerene as the parent hydrocarbon is one of the constituents of Erythroxylon monogynum (Araliaceae) its (-)-enantiomer is found in the ethereal oils of some conifers such as Thujopsis dolabrata and Cupres-sus macrocarpa (Cupressaceae). (+)-15-Beyeren-3-one occurs in the Tambooti wood from Spirostachys africana, and (+)-7-hydroxy-15-beyeren-19-oic acid was isolated from Stevia aristata (Asteraceae). 

Lathyranes are, for the most part, isolated from Euphorbiaeeae. Representatives include 7p-hydroxylathyrol from Euphorbia lathyris, the cinnamic acid esters denoted as joUcinols from E. jolkini, and ingol, a skin-irritating and antineoplastic hydrolyzate obtained from E. ingens and E. kamerunica. 

Figure 1.3 Scheme of synthesis of 2,2-a7l-substituted cinnamic acid esters. (Reproduced with permission from Ref [36].)... 

American storax and Levant storax are reported to contain similar constituents in highly variable concentrations, including free cinnamic acid (5-15%), 5-10% styracin (cinna-myl cinnamate), about 10% phenylpropyl cinnamate, a resin (storesin) consisting of triterpenic acids (oleanolic and 3-epioleanolic acids) and their cinnamic acid esters, and a volatile oil. The volatile oil present in Levant storax is usually less than 1%, but that in American storax has been reported to range from less than 7% to over 20% (arctander ... 

Phenyl-2-propenoic acid [621 -82-9] commonly referred to as cinnamic acid, is a white crystalline soHd having a low intensity sweet, honeylike aroma. It has been identified as a principal constituent in the botanical exudates from Styrax IJquidamber orientalis) Benzoin Styrax ben in Pern Balsam [Myroxylon pereirae and Tolu Balsam (]Ayro>ylon balsamum) (4,5). In these, as well as numerous other natural products, it exists both as the free acid and in the form of one or more of its esters, as for example, methyl cinnamate, ben2yl cinnamate [103 1 -3] and cinnamyl cinnamate. 

Esters can be obtained from halogenated olefins using a metal carbonyl catalyst (87), eg, /n j -l-bromo-2-phenylethylene is treated with nickel carbonyl in the presence of methanol to afford the corresponding methyl cinnamate (see Cinnamic acid). 

Hahlbrock K, Grisebach H (1970) Formation of coenzyme a esters of cinnamic acids with an enzyme preparation from cell suspension cultures of parsley. FEBS Lett ll(l) 62-64... 

Naimochelin C (Fig. 15, 54) from the myxobacterium Nannocystis exedens contains two L-Lys and two ( )-cinnamic acid units. The reported mono- and di-methyl esters (nannochelin B and A) may be artifacts from the work-up (198). A synthesis is described (29) (see Sect. 8.4). The ochrobactins (Fig. 15,55) isolated from the sea-shore bacterium Ochrobactrum sp. (214) with the spacer L-lysine are membrane active due to the fatty acid residues (saturated Cg and (2 )-unsaturated Cg and Cio) cf. lipopeptidic siderophores in Sect. 2.8. 

As reported for all pentasaccharides from sweet potato (64, 86), pure compounds 232 and 233 were also submitted to sapoiufication yielding simonic acid B (87). The liberated fatty acids were identified as isobutyric, (25)-methyIbutanoic, -decanoic, -dodecanoic, and cinnamic acids. The site of lactonization by the aglycone in the macrocyclic unit was placed at C-2 of the second saccharide. The position of the ester linkage on the macrocyclic unit was C-2 of the terminal rhamnose. The acylations were identified as follows for the macrocyclic unit at C-2 of the third saccharide (n-dodecanoic acid), and at C-3 and C-4 of the branched... 

Cinnamaldehyde, by reduction of cinna-monitrile with Raney nickel alloy in formic acid, 51,25 from the ester-mesylate, 51,76 Cinnamic acid, 50,18 CINNAMONITRILE, 50,18 Condensation, of p-acetylbenzenediazo-nium bromide with acrylic acid, 51,1... 

In its original form, the Michael addition consisted on the addition of diethyl malonate across the double bond of ethyl cinnamate in the presence of sodium ethoxide to afford a substituted pentanedioic acid ester. Currently, all reactions that involve a 1,4-addition of stabilized carbon nucleophiles to activated 7i-systems are known as Michael additions. Among the various reactants, enolates derived from p-dicarbonyl compounds are substrates of choice due to their easy deprotonation under mild conditions. Recently, Michael addition-based MCRs emerged as highly potential methodologies for the synthesis of polysubstituted heterocycles in the five- to seven-membered series. 

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