Hydroxy cinnamic alcohols

Lignans and lignins are both composed of the hydroxy cinnamic alcohols (monohgnols) />-cotmiaryl alcohol, coniferyl alcohol, and... 

There are several examples in the literature where similar cis-trans isomerizations of o-hydroxy cinnamic acid derivatives have been used to deliver fragrances. For example, ester 76, which was absorbed into cloth and exposed to sunlight, released its fragrant alcohol moiety, whereas samples that were stored in the dark did not... 

Coniferyl Alcohol, 4-(3-Hydroxy l-propenyl -2-mthoxyphetfOl 3 (4 hydroxy 3 methoxyphenyt)-2-propen-1 -of 4-hydroxy-3-methoxy cinnamic alcohol y-hydroxyisoeu-eenol. Ci8H.2Oj mol wt 180.20. C 66.65%, H 6.7 l%> O 26.64%. In benzoin, especially Siam benzoin, as coniferyl benzoate (up to 78%) Reinitzer, Arch. Pharm. 264, 131... 

Hydroxybenzyl alcohol, 2888 6-Hydroxycaespitol, 2892 Hydroxycinnamates, 1549 Hydroxy cinnamic acid amides, 1604 Hydroxycinnamic acids, 1953, 2346, 2589 Hydroxycitronellal, 2999... 

Other strains, like VLl, were selected for their low vinyl-phenol production. These compounds possess rather unpleasant pharmaceutical aromas. Above a certain concentration, they dull the aroma of dry white wines (Volume 2, Sections 8.4.2 and 8.4.3). These strains have low cinnamate decarboxylase activity. During alcoholic fermentation, this enzyme catalyzes the partial transformation of p-coumaric and ferulic acid found in juice into vinyl-4-phenol and vinyl-4-gaiacol. Since this enzyme is inhibited by phenolic compounds, only white wines can contain quantities of vinyl-phenols likely to affect their aroma. The use of strains with low cinnamate decarboxylase activity is recommended— particularly for white juices containing high concentrations of hydroxy cinnamic acid. 

The Cu(I)-catalyzed cyclization for the formation of ethyl ( )-tetrahydro-4-methylene-2-phenyl-3-(phenylsulfonyl)furan-3-carboxylate 82 has been accomplished starting from propargyl alcohol and ethyl 2-phenylsulfonyl cinnamate. Upon treatment with Pd(0) and phenylvinyl zinc chloride as shown in the following scheme, the methylenetetrahydrofuran 82 can be converted to a 2,3,4-trisubstituted 2,5-dihydrofuran. In this manner, a number of substituents (aryl, vinyl and alkyl) can be introduced to C4 <00EJO1711>. Moderate yields of 2-(a-substituted N-tosyIaminomethyl)-2,5-dihydrofurans can be realized when N-tosylimines are treated with a 4-hydroxy-cis-butenyl arsonium salt or a sulfonium salt in the presence of KOH in acetonitrile. The mechanism is believed to involve a new ylide cyclization process <00T2967>. 

A recently published full account of another synthesis [69] of the same alkaloid starting from the /rans-cinnamic ester 264 represented a different approach (ACD -> ACDB) to ( )-lycorine (Scheme 42). An intramolecular Diels-Alder reaction of 264 in o-dichlorobenzene furnished the two diastereomeric lactones 265 (86%) and 266 (5%) involving the endo and exo modes of addition respectively. The transposition of the carbonyl group of 265 to 267 was achieved by reduction with lithium aluminium hydride, followed by treatment of the resulting diol with Fetizon s reagent, which selectively oxidised the less substituted alcohol to give isomeric 5-lactone 267. On exposure to iodine in alkaline medium 267 underwent iodolactonisation to afford the iodo-hydroxy y-lactone 268. The derived tetrahydropyranyl ether... 

Later, Tressl et al. (1976) also proceeded to the thermic degradation (2 h, 200 JC) of ferulic acid (H.87) and identified the same phenols as Fiddler et al., plus 4-isopropylguaiacol and vanillin alcohol (4-hydroxy-3-methoxybenzenemethanol) which have not been found in coffee. For isoeugenol (H.38), the formula is written as the (E)-( trans -) isomer, but nothing was specified in the text. Tressl et al. (1976) also published the results of thermal decomposition of cinnamic, p-coumaric (H.84) and sinapic (H.90) acids. Many of the simple phenols (and other aromatic compounds) formed have also been identified in roasted coffee volatiles. A thermic fragmentation of quinic acid (E.62) has shown that simple acids, phenols and polyphenols originate from this precursor (Tressl et al., 1978a). 

The rearrangement of (a-hydroxyalkyl)phosphonate into phosphate ester is not universal (l-hydroxy-2-nitroalkyl)phosphonic esters do not rearrange under the influence of heat whether aided, or not, by added base and the reaction between (Me0)2P(0)H and MeCOCH=CHPh at 130-160 °C yields the 1,2-adduct (105 R = Me) which is stable to base (MeO or EtjN). On the other hand, 105 (R = H) partially decomposes in the presence of MeO and the products include the phosphate 106 together with methyl cinnamate and cinnamyl alcohol, as might be expected from the action of base on cinnamaldehyde Other compounds which undergo base-catalysed rearrangements include 107, the indanones 108 (R = H or the hydroxy phosphinic esters 109 (X = O or S, R =... 

Figure 3.1 Primary flux of carbon through phenylpropanoid pathway in Arabidopsis. PAL, phenylalanine ammonia-lyase 4CL, 4-(hydroxy)cinnamoyl CoA ligase C4H, cinnamate 4-hydroxylase HCT, hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyltransferase C3 H, /7-coumaroylshikimate 3 -hydroxylase CCoAOMT, caffeoyl CoA O-methyltransferase F5H, ferulate 5-hydroxylase COMT, caffeic acid/5-hydroxyferulic acid o-methyltransferase CCR, cinnamoyl CoA reductase CAD, cinnamyl alcohol dehydrogenase. Not depicted is the HCT catalyzed synthesis of/r-coumaroyl quinate.

In the case of aromatic esters, a few groups such as nitro and bromo survived at the reduction conditions, whereas hydroxy and amino groups completely suppressed the reaction. Considering the case of ethyl cinnamate, the fully saturated alcohol was the sole product of the reduction. In all the examined cases a molar ratio of NaBH /ester of 3 1 was always used in order to achieve the best yields. 

Cinnamaldehyde Cinnamic Aldehyde 107-19-7 3-Hydroxy-l-Propyne Propargyl Alcohol... 

Rayon, cellophane Cellulose acetate Cellulose nitrate Hydroxy ethyl cellulose Carboxy methyl cellulose Ethyl cellulose Methyl cellulose Polyvinyl alcohol Polyvinyl butyral Polyvinyl formal Brominated butyl rubber Polyvinyl cinnamate Cellulose nitrate (guncotton) Chlorinated rubber Graft copolymer... 

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