Cinnamic aldehyde,— KETONES

Claisen reaction Condensation of an aldehyde with another aldehyde or a ketone in the presence of sodium hydroxide with the elimination of water. Thus benzaldehyde and methanal give cinnamic aldehyde, PhCH CH-CHO. 

Pyruvic Acid Compounds.—Lubrzynska and Smedley have recently shown that a number of aldehydes such as heliotropin, anisic aldehyde, benzaldehyde, and cinnamic aldehyde, condense with pyruvic acid in slightly alkaline solution, with the formation of )8-unsaturated-a-ketonic acids. For example, if heliotropin and pyruvic acid in alkaline solution be left standing for about eight days at ordinary temperature, dihydroxy-methylene-benzal-pyruvic acid is formed. This body forms yellow needles, melting at 163° Similarly, anisic aldehyde yields methoxy-benzal-pyruvic acid, melting at 130° and cinnamic aldehyde yields cinnamal-pyruvic acid, melting at 73°. 

Sadtler concluded finally that double bonds seem to aid in bringing about reaction when close to the. CHO group, e.g., citral, cinnamic aldehyde, and that proximity of the benzene nucleus to the. CHO group, as. in the case of benzaldehyde and vanillin, was also probably a factor, while the only active ketones were those containing double bonds near to the. CO group. 

The enantioselective addition of organomagnesium compounds to ketones can be most conveniently performed by using a chiral auxiliary in the substrate molecule. Primary aUsyhnagnesium reagents react with aryl and heteroaryl ketones in the presence of magnesium TADDOLate at — 100°C, yielding products with up to 98% ee (equation 143). Chiral a-ketoacetals 214, prepared in two steps from a-substituted cinnamic aldehydes, add organomagnesium species with up to 98% diastereoselectivity (equation 144). 

Cinnamomum zeglanicum Blume Ceylon Rou Gui (Ceylon cinnamon) (bark) Cinnamic aldehyde, p-cymene, hydrocinnamic aldehyde, pinene, benzaldehyde, cuminic aldehyde, nonylic aldehyde, eugenol, caryophyllene, 1-phellandrine, methyl-n-amyl ketone, 1-linalool.60 Stimulant to digestion, respiration, circulation. 

Aldehydes (e.g., citral, cinnamic aldehyde, etc.) and certain ketones e.g., acetone) react with hydroxylamine hydrochloride forming oximes with the liberation of hydrochloric acid (Z. a., 1895, 623) which can be titrated in presence of methyl orange. 

This topological rule readily explained the reaction product 211 (>90% stereoselectivity) of open-chain nitroolefins 209 with open-chain enamines 210. Seebach and Golinski have further pointed out that several condensation reactions can also be rationalized by using this approach (a) cyclopropane formation from olefin and carbene, (b) Wittig reaction with aldehydes yielding cis olefins, (c) trans-dialkyl oxirane from alkylidene triphenylarsane and aldehydes, (d) ketenes and cyclopentadiene 2+2-addition, le) (E)-silyl-nitronate and aldehydes, (f) syn and anti-Li and B-enolates of ketones, esters, amides and aldehydes, (g) Z-allylboranes and aldehydes, (h) E-alkyl-borane or E-allylchromium derivatives and aldehydes, (i) enamine from cyclohexanone and cinnamic aldehyde, (j) E-enamines and E-nitroolefins and finally, (k) enamines from cycloalkanones and styryl sulfone. 

If tW molecular quantities of cinnamic aldehyde be used, thou in the last case di-cinnamyl-vinyl ketone results. 

Crossed aldol condensations between benzaldehyde or cinnamic aldehyde or their derivatives ketones pose no chemoselectivity problems. The least sterically hindered ketone, acetone, may condense with benzaldehyde, cinnamic aldehyde, and their derivatives with both enolizable positions if an excess of the aldehyde is employed. 

In the first type, which includes aldehyde C12 lauric and phenylacetaldehyde, the balance of the reaction lies in favor of the combined molecule. In the second, however, to which belong aldehyde C12 MNA, cyclamen aldehyde, hydratropic aldehyde, and Lilial, the balance lies more toward the original material. Most ketones also behave in this way. The third type, which includes amyl and hexyl cinnamic aldehydes, do not undergo the aldol reaction and are therefore more stable. Aldehydes such as anisaldehyde and Triplal, in which the —CHO is linked directly to a ring structure, are also less reactive. 

It has also been found that certain aldehydes, ketones and carboxylic acids esters form well defined products with nitric acid (Reddelien [5]). For example, bemzaldehyde with 60% nitric acid gives a colourless, unstable oil, and cinnamic aldehyde forms fairly stable white crystals, melting at 60-61°C, with 65% nitric acid. Acetophenone, benzophenone, fluorenone, phenanthrenoquinone and camphor give similar addition products. 

No colour appears with some aldehydes, for example, furfural and cinnamic aldehyde. Bitto has suggested this reaction may be used for the identification of aldehydes and ketones (see also p. 239). 

Yb(fod)j catalyzed the addition of benzocyclopropene to the carbonyl bond of benzaldehyde and its derivatives the corresponding 1,3-dihydroisobenzofurans 16 were isolated in 17-66% yield. Cinnamic aldehydes and ketones also react via attack at the carbonyl group rather than at the C-C double bond to give 17. These additions also proceed in the absence of a catalyst, but with much lower yields. 

Cedergren-Zeppezauer E, Samama J-P, Eklund H (1982) Crystal structure determinations of coenzyme analogue and substrate complexes of liver alcohol dehydrogenase Binding of 1,4,5,6-tetrahydronicotin-amide adenine dinucleotide and trans-4-(N,N-dimethylamino)cinnam-aldehyde to the enzyme. Biochemistry 21 4895-4908 Cherest M, Felkin H, Prudent N (1968) Tortional strain involving partial bonds. The stereochemistry of the lithium aluminium hydride reduction of some simple open-chain ketones. Tetrahedron Lett 2199-2204... 

Aminocinnamoyl compounds (accessible by reduction of the corresponding 2-nitro compounds) undergo cyclization to give quinoline derivatives thus, from 2-nitro-cinnamic aldehydes or -ketones quinoHnes 65 are obtained, while from 2-nitrocinnamic adds the products are 2-quinolones 66 ... 

According to Schimmel Co. about 97 per cent, of patchouli oil consists of bodies of no value for odour purposes. They have detected the following constituents in patchouli oil benzaldehyde eugenol cinnamic aldehyde a terpenic alcohol of rose-like odour and of undetermined constitution a ketone of caraway odour forming a semi-carbazone melting at 134° to 135° and a base of stupefying odour not yet identified. But as all these bodies are present in traces only it cannot be said that our knowledge of the odour bearers present in patchouli oil is complete. 

Pinene 2-8% pinene 1-4% myrcene 1-12% of-pheUandrene 1-25% Hmonene 8 30% fenchone 7-16% estragole 2-7% cw-anethole <0.5% rra/ii-anethole 15-40% anise ketone <0.05% tasmanian-type a -pinene 2-11% a-pheUandrene 1-8.5% hmonene 1 % fenchone 10-25% estragole 1.5-6% cis-anethole <0.5% trans-anethole 45-78% anisaldehyde <1% anisketone <0.05% /S-myrcene 0.1-1% hmonene 30-45% trans-dihydrocarvone max. 2.5% carvone 50-65% trans-casrveoh max. 2.5% trans-cinnamic aldehyde 70-90% cinnamyl acetate 1-6% eugenol <0.5% coumarin 1.5-4% rra s-2-methoxy-cinnamaldehyde 3-15%... 

Monohydric alcohols, aldehydes (including chloral hydrate), ketones, cinnamic acid, amines (2-naphthylaminc is odourless), nitrophenols (resemble both phenol and nitro-compound),... 

Reactions. Heating an aqueous solution of malonic acid above 70°C results in its decomposition to acetic acid and carbon dioxide. Malonic acid is a useful tool for synthesizing a-unsaturated carboxyUc acids because of its abiUty to undergo decarboxylation and condensation with aldehydes or ketones at the methylene group. Cinnamic acids are formed from the reaction of malonic acid and benzaldehyde derivatives (1). If aUphatic aldehydes are used acryhc acids result (2). Similarly this facile decarboxylation combined with the condensation with an activated double bond yields a-substituted acetic acid derivatives. For example, 4-thiazohdine acetic acids (2) are readily prepared from 2,5-dihydro-l,3-thiazoles (3). A further feature of malonic acid is that it does not form an anhydride when heated with phosphorous pentoxide [1314-56-3] but rather carbon suboxide [504-64-3] [0=C=C=0], a toxic gas that reacts with water to reform malonic acid. 

Isomerization has been observed with many a,j3-unsaturated carboxylic acids such as w-cinnamic 10), angelic, maleic, and itaconic acids (94). The possibility of catalyzing the interconversion of, for example, 2-ethyl-butadiene and 3-methylpenta-l,3-diene has not apparently been explored. The cobalt cyanide hydride will also catalyze the isomerization of epoxides to ketones (even terminal epoxides give ketones, not aldehydes) as well as their reduction to alcohols. Since the yield of ketone increases with pH, it was suggested that reduction involved reaction with the hydride [Co" (CN)jH] and isomerization reaction with [Co (CN)j] 103). A related reaction is the decomposition of 2-bromoethanol to acetaldehyde... 

Reactions. Malonie acid is a useful tool lor synthesizing a-unsaturaled carboxylic acids because of its ability lo undergo decarboxylation and condensation with aldehydes or ketones at the methylene group. Cinnamic... 

Cinnamic acid, a-(/9-HYDROXYSTYRYL)-, y-LACTONE, 43, 3 Cinnamyl bromide, 44, 32 Condensation, of aldehydes and ketones with esters to give (S-hydroxy-esters, 44, 58... 

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