Phenylglyoxylic acid reaction with

The first report concerning an asymmetric Paterno-Buchi reaction with a chiral carbonyl component was reported in 1979 by Gotthardt and Lenz [128]. The photocycloaddition of the enantiomerically pure menthyl ester of phenylglyoxylic acid 133 with 2,3-dimethyl-2-butene gave the oxetane 134 with a diastereomeric excess of only 37% (Sch. 45). 

A similar dependence of the stereoselectivity on the solvent and reaction temperature was found with the x-oxo amides 9 derived from phenylglyoxylic acid (R = C6H5) and 2-oxopropanoic acid (R = CH3) with amine F (Table 23)15. Thus, the highest selectivity was observed under chelation-controlled conditions in the presence of the Lewis acid titanium(IV) chloride. 

Fig. 5.38 Reduction of 10-3m phenylglyoxylic acid at the mercury streaming electrode in acetate and phosphate buffers containing 1 m KN03 (1) pH 5.02, (2) pH 5.45, (3) pH 5.85, (4) pH 6.25. The curves 2, 3 and 4 are shifted by 0.2 V, 0.4 V and 0.6 V with respect to curve 1. The first wave is controlled by the surface protonation reaction while the second is a direct reduction of the acid anion. (According to J. Koryta)...

Deuterium isotope effects in the reactions of 2-nitroso-2-methyl propane with formaldehyde, glyoxylate, glyoxylic acid, pyruvic and phenylglyoxylic acid... 

The oxidation of methyl ketones to a-keto carboxylic acids is rare and is accomplished by treatment with a cold solution of potassium permanganate. However, the reaction is not general acetophenone, p-methyl-acetophenone, and 3,4-dimethylacetophenone are oxidized all the way to the corresponding benzoic acids. On the other hand, 2,4-dimethylaceto-phenone, when shaken with approximately 1% aqueous potassium permanganate at room temperature, gives 6 72% yields of 2,4-dimethyl-phenylglyoxylic acid [555, 559],... 

The structure assigned to mandelic acid is in accord with its reactions. It is oxidized by an alkaline solution of potassium permanganate in the cold to phenylglyoxylic acid —... 

Another MW-assisted application of the Ugi-de-Boc cyclization sequence (vide supra) is the construction of the interesting N-containing heterocyclic core of a qui-noxalinone 48. When the reaction was performed at room temperature good yields were obtained but it took 36-48 h to complete [89]. Tempest et al. modified the procedure to reduce reaction times and to simplify the purification of the Ugi condensation products [75]. They did this by irradiating a mixture of F-Boc protected diamine with a slight excess of phenylglyoxylic acid 46, aldehyde, and isonitrile in MeOH in a monomode MW reactor for 10-20 min at 100 °C, initially obtaining intermediate 47 (Scheme 17.35). 

A new synthesis of L-apiose uses the photochemical reaction of the (-)-8-phenylmenthyl ester of phenylglyoxylic acid with 2,2-di-methyl-1,3-dioxalen to generate the oxetan (18) with 96% d.e., leading in turn to the branched-chain sugar (19) and the apioside (20)(Scheme 7). ... 

The ring-closure of 3-methoxyphenyl thioacetate in concentrated sulphuric acid gives 3-methyl-6-methoxybenzo[6]thiophen in good yield. 2-Phenylbenzo[6]thiophen-3-carboxylic acids have been synthesized by the reaction of thianaphthenquinones (340) with a-chlorophenylacetic acid, followed by cyclization of the o-(carboxybenzylthio)phenylglyoxylic acid (341) isolated as an intermediate. - These benzo[f>]thiophencarboxylic... 

Although the mechanisms of the oxidations of organic mono- and di-carboxylic acids have been much examined under acidic conditions, the faster reactions in alkaline media have only recently been investigated. In contrast to the reaction in acidic solution where, with mandelic acid as substrate, oxidative decarboxylation occurs to yield benzaldehyde and CO2, at the higher pH the product is phenylglyoxylic acid ... 

FMO calculations using PM3-C1 were used to investigate the regioselectivities obtained by the photochemical reactions between 2-pyridone and pcnta-2,4-dienoate.46 The hard and soft acid-base principle has been successfully used to predict product formation in Patemo-Buchi reactions.47 The 2 + 2-photo-cycloaddition of homobenz-valene with methyl phenylglyoxylate, benzyl, benzophenone, and 1,4-benzoquinone produced the corresponding Patemo-Buchi products.48 The photo-cycloaddition of acrylonitrile to 5-substituted adamantan-2-ones produces anti- and svn-oxetanes in similar ratios irrespective of the nature of the 5-substituent49... 

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