Cinnamate VIII

DMA in 500 ml ether mix rapidly with 270 ml 0.9 M phenyl-Li, boil fifteen hours and extract as for (VI) or as described previously to get 8 g oily 4-methoxy-indoline (or its 1-methyl derivative) (VII). Alternatively, add 36 g naphthalene to 300 ml tetrahydrofuran and add 11 g Na metal cut in small pieces. Reflux and stir three hours and add 18 g (VI) and 8 g DEA in 200 ml tetrahydrofuran rapidly and boil twelve hours. Evaporate in vacuum, dissolve the oily residue in 2N HCI and extract with ether. Proceed as described to get (VII). 4 g (VII) in 200 ml dry pyridine add to 6 g Cu chloride in 400 ml pyridine and reflux 1 xh hours. Pour on water and extract with ether. Wash extract with 4N HCI and then water and dry and evaporate in vacuum the ether to get 2 g of the indole (VIII). Alternatively, dissolve 4 g (VII) and 9.5 g cinnamic acid in 700 ml mesitylene, add 1 g 5% palladium-carbon and reflux five hours. Filter, wash with HCI and NaHC03 and dry and evaporate in vacuum the mesitylene to get the red, oily (VIII) (can chromatograph on alumina and elute with benzene-petroleum ether). 

Table VIII shows the dramatic differences between fresh and dried leaves. In this case, as oj sed to peppermint, rosemary and thyme, trans-2-hexenal is more in the fresh than in the dried and aged. The same is true for phenyl ethyl alcohol. Interestingly, trans-cinnamic aldehyde constitutes 50% of the total living headspace volatiles, but it is still less than in the aged leaf and commercial oil. However, cinnaniyl alcohol represents 20% of the fresh volatiles but is only a trace conpcanent of the aged leaf and oil. 4-Methoxy cinnamic aldehyde, identified as a cassia constituent for the first time, also increases 3-fold on drying but has disappeared completely in the comtnercial oil. 2-Methoxy cinnamic aldehyde, sometimes called the character impact component of cassia oil, is present in the headspace of the leaves to only a minor extent but it is the second most abundant component of the oil.

Cohen, M.D. and Schmidt, G.M. (1964) Topochemistry. Part VIII. The photochemisry of troras-cinnamic acids. 

Readily available i-propylcinnamate was treated with 1.10 mol equiv. of /V-bromoacet-amide, 1.07 mol equiv. of LiOH, and catalytic amounts of both Os(VIII) (0.015 mol equiv.) and the dihydroquinine-derived ligand 85 (0.01 mol equiv.) in a t-BuOH/water mixture as solvent. From this reaction, carried out on a 630 mmol scale, N-acetyl ra-hydroxy-p-aminoester 86 was isolated by crystallization in 71% yield and 99% e.e. When the reaction was run on a smaller scale, chromatographic purification gave the product in 81% yield. Acid hydrolysis of 86 afforded (2R,3S)-phenylisoserine 87 as its hydrochloride in 68% overall yield from the cinnamate. 

Damen and Neckers (111) were more successful in this respect. They also used cyclobutane derivatives and copolymerized the bis(vinylbenzyl)ester of a-truxillic acid, 3 truxinic acid, and 6-truxinic acid. After removing the template, trans-cinnamic acid was bound to each pair of benzyl alcohols in a cavity. Irradiation of the polymers yielded dimerization of the trans-cinnamic acid. Table VIII shows the composition of the products from hydrolysis of the polymers. 

Table VIII. Photochemical Reaction of trans-Cinnamate-Esters Bound to Imprinted Cavities (111)...

For the dimerization of trans-cinnamate esters bound to a random polymer the exclusive formation of a-truxillic acid is expected. Table VIII shows indeed a considerable stereochemical direction of the photochemical reaction by the imprinting procedure. 

The reaction of benzyl chloride with metallic nickel in the presence of methyl acrylate was carried out at 85°C, and the expected addition product methyl 4-phenylbutanoate was formed in 17% yield (Equation 7.12). The reaction with acrylonitrile gave 4-phenylbutanenitrile in 14% yield together with cis- and tra 5-4-phenyl-2-butenenitriles, 4-cyano-6-phenylhexanenitrile, and 2-ben-zyl-4-phenylbutanenitrile (Equation 7.13). The results suggest the presence of a benzylnickel(II) chloride complex (1), which could have been formed by the oxidative addition of benzyl chloride to the metallic nickel (Scheme 7.7). The complex (I) would then be expected to add to the electron-deficient olefins, affording the addition product (111) via intermediate complex (IV). The formation of cis- and tra s-4-phenyl-2-butenenitrile (V) is reasonably explained by the reductive elimination of nickel hydride from intermediate (IV), which is analogous to the substitution reaction of olefins with alkylpalladium compound [158] and to the addition-elimination reaction of bis(triphenylphosphine) phenylnickel(II) bromide with methyl acrylate to yield methyl cinnamate [130]. Furthermore, intermediate (IV) seems to add another molecule of acrylonitrile to give the 1 2 adduct 4-cyano-6-phenylhexanenitrile (VI). 2-Benzyl-4-phenylbutanenitrile (VIII) would be formed by the metathesis of complex IV and the benzylnickel chloride (I). 

The aroma of peaches is characterized by y-lactones (C6-C12) and 5-lactones (Cio and Cl2). The main compound in the lactone fraction is (R)-l,4-decanolide, which has a creamy, fruity, peach-like odor. Other important compounds should be benzaldehyde, benzyl alcohol, ethyl cinnamate, isopentyl acetate, linalool, a-terpineol, a- and 3-ionone, 6-pentyl-a-pyrone (Formula 18.39, VIII), hexanal, (Z)-3-hexenal, and (E)-2-hexenal. Aroma differences in different varieties of peaches are correlated with the different proportions of the esters and monoterpenes. In the case of nectarines (Prunus persica L., Batsch var. nucipersica Schneid), the lactones y-C8-Ci2 and 5-Cio belong to the compounds with the highest aroma values. 

Amarouche, H., De Bourayne, C., Riviere, M., and Lattes, A., Chemical and photochemical reactivity in micellar media and microemulsions. VIII. Photoreactivity of cinnamate derivatives in microemulsions, C. R. Acad. Sci. Ser. 2, 298,121,1984. 

---