Cinnamic alcohol, oxidation

Cinnamic alcohol forms a phenyl-urethane, melting at 90° to 91°, and a diphenyl-urethane, melting at 97° to 98°. On oxidation it yields cinnamic acid, melting at 133°, and by more thorough oxidation, benzoic acid, melting at 120°. 

Cinnamic alcohol can be dehydrogenated to give cinnamaldehyde and oxidized to give cinnamic acid. Hydrogenation yields 3-phenylpropanol and/or 3-cyclo-hexylpropanol. Reaction with carboxylic acids or carboxylic acid derivatives results in the formation of cinnamyl esters, some of which are used as fragrance materials. 

Valechha, N. D., Pandey, A. K. Kinetics of oxidation of allyl, crotyl and cinnamic alcohols by selenium dioxide. J. Indian Chem. Soc. 1986, 63, 670-673. 

Needles or cryst mass. Odor of hyacinth, mp 33. d 1.0397. bPL0 72.6" bp, 102.5" bp,0 117.8" bp 133.7 bp 151.0s bp 162.0s bpIM 177.8s hp, 199.8) bp , 224.6" bp, 2503 . n 1.58190 n 1.57580. When smallamounts of impurities are present as in the natural article (cinnamyl alcohol from storax), it remains fluid at lower temps than the melting point. Minimum congealing points specified by the Essentia] Oil Assn are 33.0s for cinnamic alcohol pure 28.0s for cinnamic alcohol prime 20.0s for cinnamic alcohol from storax. [s oxidized slowly on exposure to heat, light and air. So] in water, glycerol. Clearly sol in 3 vols 50% ale. Freely sol in ale, ether, other common organic solvents. 

Ckmamyl alcohol (cinnamic alcohol, 3-phenyl-2-pro-pen-l-ol). H5C -CH=CH-CH20H, C,H, 0, Mr 134.17, ( )-form needles with a sweet-balsamy, hyacinth-like odor, mp. 33°C, bp. 258°C, bp. 142-145 C (1.86 kPa), readily soluble in alcohol and ether, it is slowly oxidized by atmospheric oxygen under warmer conditions and on exposure to light. It occurs mostly in the form of cinnamic acid esters (see cinnamic acid) in storax (oil), peru balsam, cinnamon leaf, narcissus, and hyacinth oils. 

Equimolar amounts of cinnamic alcohol and Na-dichromate mixed with water, and refluxed 3 hrs. cinnamaldehyde. Y 91% conversion 87%. - Similarly during 2 hrs. a-Phenylethanol acetophenone. Y 96% conversion 50%. - This oxidation by neutral aq. Na-dichromate is particularly recommended for benzylic alcohols. F. e. and limitations s. D. G.Lee and U. A. Spitzer, J. Org. Chem. 55, 3589 (1970). 

IFRA and RIFM have forbidden the use of several essential oils and components, including costus root oil, dihydrocoumarin, musk ambrette, and balsam of Peru (Ford, 1991) a concentration limit is imposed on the use of isoeugenol, cold pressed lemon oil, bergamot oil, angelica root oil, cassia oU, cinnamic alcohol, hydroj citronellal, and oakmoss absolute. Cinnamic aldehyde, citral, and carvone oxide can only be used with a quenching agent. 

The direct transformation of alcohols to the corresponding amines is of growing interest because alcohols are easily available or accessible by chemical means. Amination of alcohols is usually catalyzed by transition metals at high temperatures and elevated pressures. Unfortunately, there is no enzyme known today that allows this particular functional group interconversion (FGl) in one step. Consequently, a multi-enzyme cascade was set up for the amination of alcohols as demonstrated for various benzylic and cinnamic alcohols under physiological conditions [24] aerobic alcohol oxidation toward the aldehyde was performed via a galactose oxidase originating from Fusarium (NRRL 2903 [25]) followed by an in situ co-TA-catalyzed reductive amination step (Scheme 4.5). 

Use 01 g. of the platinum oxide catalyst and 11 4 g, of pure cinnamic acid dissolved in 100 ml. of absolute alcohol. The theoretical volume of hydrogen is absorbed after 7-8 hours. Filter off the platinum, and evaporate the filtrate on a water bath. The resulting oil solidifies on cooling to a colourless acid, m.p. 47-48° (11-2 g.). Upon recrystallisation from light petroleum, b.p. 60-80°, pure dihydrocinnamic acid, m.p. 48-49°, is obtained. 

Hydrocinnamic acid may also be prepared by the reduction of cinnamic acid with sodium and alcohol or with sodium amalgam or with hydrogen in the presence of Adams platinum oxide catalyst (Section 111,150) ... 

Pyrolytic Decomposition. The pyrolytic decomposition at 350—460°C of castor oil or the methyl ester of ricinoleic acid spHts the ricinoleate molecule at the hydroxyl group forming heptaldehyde and undecylenic acids. Heptaldehyde, used in the manufacture of synthetic flavors and fragrances (see Elavors and spices Perfumes) may also be converted to heptanoic acid by various oxidation techniques and to heptyl alcohol by catalytic hydrogenation. When heptaldehyde reacts with benzaldehyde, amyl cinnamic aldehyde is produced (see Cinnamic acid, cinnamaldehyde, and cinnamyl... 

The oxidative carbonylation of styrene with carbon monoxide, oxygen, and an aUphatic alcohol in the presence of a palladium salt, a copper salt, and sodium propionate also provides the requisite cinnamate. 

When heated in the presence of a carboxyHc acid, cinnamyl alcohol is converted to the corresponding ester. Oxidation to cinnamaldehyde is readily accompHshed under Oppenauer conditions with furfural as a hydrogen acceptor in the presence of aluminum isopropoxide (44). Cinnamic acid is produced directly with strong oxidants such as chromic acid and nickel peroxide. The use of t-butyl hydroperoxide with vanadium pentoxide catalysis offers a selective method for epoxidation of the olefinic double bond of cinnamyl alcohol (45). 

Bartoli recently discovered that by switching from azide to p-anisidine as nucleophile, the ARO of racemic trans- 3-substituted styrene oxides could be catalyzed by the (salen)Cr-Cl complex 2 with complete regioselectivity and moderate selectivity factors (Scheme 7.36) [14]. The ability to access anti-P-amino alcohols nicely complements the existing methods for the preparation of syn-aryl isoserines and related compounds [67] by asymmetric oxidation of trans-cinnamate derivatives [68]. 

Kinetics of the reaction of diazodiphenylmethane (92) in a wide range of alcohols with pyridine and pyridine-A -oxide 3- and 4-carboxylic acids (84)-(87), 4-substituted benzoic acids (88)," cw -substituted cinnamic acids (89), 2-(4-phenyl-substituted)cyclohex-l-enyl carboxylic acids (90), and 4 -substituted-biphenyl-2-carboxylic acids (91)" have been reported. Comparison of the new results for 4-substituted benzoic acids with the published results of data for 3-substituted benzoic acids was made, " and it was concluded that the most important solvent property influencing the rate of reaction appears to be the polarity of the alkyl group expressed as Taft s polar constant a. Transmission coefficients in the cinnamic acids (89) were compared with those in the bicyclic acids (90) and... 

Cinnamyl alcohols.1 These alcohols can be prepared by oxidation of 3-arylpropenes with selenium dioxide in dioxane. The yield compares favourably with that oblained by LiAlH4 reduction of esters of cinnamic acids. 

Benzamido-cinnamic acid, 20, 38, 353 Benzofuran polymerization, 181 Benzoin condensation, 326 Benzomorphans, 37 Benzycinchoninium bromide, 334 Benzycinchoninium chloride, 334, 338 Bifiinctional catalysts, 328 Bifiinctional ketones, enantioselectivity, 66 BINAP allylation, 194 allylic alcohols, 46 axial chirality, 18 complex catalysts, 47 cyclic substrates, 115, 117 double hydrogenation, 72 Heck reaction, 191 hydrogen incorporation, 51 hydrogen shift, 100 hydrogenation, 18, 28, 57, 309 hydrosilylation, 126 inclusion complexes, oxides, 97 ligands, 19, 105 molecular structure, 50, 115 mono- and bis-complexes, 106 NMR spectra, 105 olefin isomerization, 96... 

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