Phenyl-acetic acid aldehyde

Aldehydic notes Aldehyde CIO Benzyl phenylacetate Phenyl acetic acid Aldehyde C8... 

Mixtures of perbutyric and butyric acid were formed during oxidation of butyral-dehyde in the presence of Co(OAc)2 [243]. The oxidation of n-butyraldehyde [243-245] and 2-ethyl hexaldehyde [246] are second order in aldehyde and follow expected radical pathways. Isobutyraldehyde was oxidized using ferrocene derivatives as catalysts [247,248]. In a typical experiment isobutyric acid was produced in 97% selectivity at 60% conversion of the aldehyde. Cobalt(II) and manganese(II) acetyl-acetonates have been used in a similar manner to prepare phenyl acetic acid from phenylacetaldehyde in good yield [249,250]. 

There are several ways in which phenols have been categorized. Harbome and Simmonds categorized polyphenols based on the number of carbon atoms, which includes simple phenols (Ce) phenolic acids and related compounds (Ce—Ci) acetophenones and phenyl acetic acids (Cg—C2) cinnamic acids, cinamyl aldehydes, and alcohols (Cg—C3) coumarins, isocoumarins, and chromones (Cg—C3) flavonoids (C15) biflavonyls (C30) stilbenes (Cg—C2—Cg) benzophenones and xanthones (Cg—C2—Cg) quinones (Cg, Cio, Cm) betacyanins (Cjg) and lignans, lignins, tannins, and phlobaphenes (which are dimmers, oligomers, or polymers) [19]. Polyphenols have also been categorized by some researchers based on their... 

A different cyclic transition state model which does, however, not incorporate the metal, has been proposed by Mulzer and coworkers. It was developed to explain the observation that in the addition of doubly deprotonated phenyl acetic acid to pivaldehyde the highest anti selectivity is obtained with the most naked enolate anions (e.g. K/18-crown-6). The hypothesis, which might explain this stereochemical result, assumes that the approach of the enolate to the aldehyde is dominated by the interaction of the enolate HOMO and the n orbital of the aldehyde that functions as the LUMO. The favored approach of the reactants occurs when the substituents of the enolate (phenyl) and the aldehyde (t-butyl) are oriented in a trans orientation at the forming carbon bond, so that their mutual steric repulsion is minimized (Scheme 1.11). The expected transition state 37 has some similarity to that of a 1,3-dipolar cycloaddition, although the corresponding cycloadduct 38 does not form, because of the weakness of the oxygen-oxygen bond. Instead, the doubly metalated aldol adduct 39 results [88]. In a similar... 

Pyrrolidinone 126 and salicylic aldehyde in acetic acid under microwave irradiation gives in dioxopyrrolo[3,4-c]benzoxepine 127 as a mixture with phenyl chromeno[2,3- ]pyrrole 128 (8 and 13% yields, correspondingly. Equation (18)... 

The condensation of an aldehyde, benzyl carbamate, and triphenyl phosphite, first described by Oleksyszyn et al., 25,26 affords a direct route to a-aminoalkylphosphonates 4 that are conveniently protected for subsequent reactions (Scheme 4). Since dealkylation of the quaternary phosphonium intermediate 3 is not possible in this case, formation of the pen-tavalent product 4 presumably involves activation of the solvent and formation of phenyl acetate. This method is useful for the synthesis of aliphatic and aromatic amino acid analogues. However, monomers with more elaborate side chains are often incompatible with the reaction conditions. The free amine can be liberated by treatment with HBr/AcOH or by hydrogenolysis after removal of the phenyl esters. The phosphonate moiety can be manipulated by ready exchange of the phenyl esters in alkaline MeOH and activation as described in Section 10.10.2.1.1. Related condensations with other trivalent phosphite derivatives have been reported. 27-30 ... 

A mixture of 5-amino-A-phenyl-l//-pyrazole-4-carboxamide 1 (0.2 g, 1 mmol), pyruvic acid 4 (0.08 g, 1 mmol) and its aldehyde 5 (0.13 g, 1 mmol) was refluxed in 3 ml of acetic acid for 2 h (Scheme A.27). After cooling, the crystals precipitated were removed by filtration, washed with ethanol and air-dried. If required, the products were crystallized from ethanol. Yield 46%. 

Aminothiazole, with acetaldehyde, 42 to 2-mercaptothiazoie, 370 4-Aminothiazole-2,5-diphenyl, to 2,5 di-phenyl-A-2-thiazoline-4-one, 421 Ammothiazoie-A -oxide, 118 2-Aminothiazoles. 12 acidity of, 90 and acrylophenone, 42 acylations of, with acetic acid. 53 with acetic anhydride, 52 with acyl halides, 48 with chloracetyl chloride, 49 with-y-chlorobutyrylchloride, 50 with 0-chloropropionylchloride, 50 with esters, 53 with ethy acrylate, 54 with indoiyl derivatives, 48 with malonic esters, 55 with malonyl chloride, 49 with oxalyl chloride, 50 with sodium acetate, 52 with unsaturated acyl chloride, 49 additions to double bonds, 40 with aldehydes, 98 alkylations, with alcohols, 38 with benzyhydryl chloride, 34 with benzyl chloride, 80 with chloracetic acid, 33 with chloracetic esters, 33 with 2-chloropropionic acid, 32 with dialkylaminoalkyl halides, 33 with dimethylaminoethylchloride, 35 with ethylene oxide, 34, 38... 

When 2-acetylphenyl tellurium bromide and aromatic aldehydes were refluxed in acetic acid in the presence of piperidine, 2-benzylidene-3-oxo-benzotellurophenes were formed in 80% yields4. These reactions were proposed to proceed via 2-(3-aryl-l-oxoprop-2-en-l-yl)-phenyl tellurium bromides that cyclize with elimination of hydrogen bromide. However, 3-oxo-2,3-dihydrobenzotellurophene cannot be ruled out as the intermediate which then condenses with the aromatic aldehydes2, because 2-acetylphenyl tellurium bromide is known to cyclize to form 3-oxo-2,3-dihydrobenzoteIIurophene2,3. 

Benzylidene-3-oxo-2,3-dihydrobenzotellurophenes were also obtained when 2-acetyl-phenyl tellurium bromide and aromatic aldehydes were refluxed in acetic acid in the presence of piperidine. 3-Oxo-2,3-dihydrobenzotellurophene could be the intermediate that condenses with the aldehydes1. 

Morpholino-li/-2-benzopyran-l-one (208) adds aromatic aldehydes in hot acetic acid or acetonitrile to form dihydro-4-morpholinocarbonyl-l/7-2-benzopyran-l-ones 209 as mixtures of cis- and trans-isomers. The process is formally an ene reaction in which an acyl group is transferred (equation 88). Analogous reactions with imines, phenyl isocyanate, nitrosobenzene, arenediazonium salts and carbon disulphide lead to a variety of heterocycles (Scheme 7)110. 

Thus, upon CIR of electron-deficient (hetero)aryl halides 11 and phenyl propargyl alcohol 12a, after subsequent Stetter reaction with aldehydes 92 in presence of catalytic amounts of thiazolium salt 93, and after addition of glacial acetic acid and concentrated HCl, the 2,3,5-trisubstituted furans 95 are obtained in moderate to good yields in a one-pot procedure (Scheme 51) [260]. 

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