2-Hydroxy-2-phenylpropionic acid

Lobeline.—The results of feeding experiments with DL-[2- C]lysine and dl-[2- Clphenylalanine in Lobelia inflata have shown that these amino-acids are both specific precursors for the alkaloid lobeline (13). In further experiments, DL-[3- C]phenylalanine, [3- C]cinnamic acid, and [3- C]-3-hydroxy-3-phenylpropionic acid [as (9)] have been found to be specific precursors for lobeline (13). These results are consistent with the anticipated pathway " to lobeline illustrated in Scheme 2, with benzoylacetic acid (10) as the intermediate which couples with A -piperideine to give the intermediate (11). The probability of 3-hydroxy-3-phenylpropionic acid (9) being an intermediate in lobeline biosynthesis is increased by the isolation of this acid from L. inflata ... 

Hydroxy-2-phenylpropionic acid, A41.10 3-Hydroxy-3-phenylpropionic acid, A23.1 Atrolactic acid, A31.19, A"44 2-Phenoxypropionic acid, A12.7, X"7, A"49 2-Hydroxymethylbenzodioxan, A"23.14... 

Bromination of a simple tyrosine analog, phloretic acid (p-hydroxy-phenylpropionic acid) (CIV), tvith two equivalents of reagent in aqueous... 

Another potentially valuable method for the preparation of cinnamic acid involves treatment of benzaldehyde with ketene (12). The initially formed oligomer of P-hydroxy-P-phenylpropionic acid is thermally decomposed at 100—250°C in the presence of an acid or base catalyst. 

L-2-Hydroxy-3-phenylpropionic acid (3-phenyl lactic acid) [20312-36-1 ] M 166.2, m 125-126 , [aJo -18.7 (EtOH), pK see below. Crystd from water, MeOH, EtOH or benzene. 

The crude iodinated acid was then dissolved in 500 ml of 95% alcohol, 10 g of dimethyl-aminoethanol was added, the solution was decolorized with activated charcoal and filtered at 70°C. After keeping the filtrate for several hours at 5°C, the heavy crystalline precipitate which formed was collected by filtration and washed with acetone. The mother liquors were concentrated to 150 ml and cooled to give a second crop which was further purified by recrystallization from 50 ml of 95% alcohol. In this way a total of 36.0 g of dimethyl-aminoethanol salt of dextro-/3-(3,5-diiodo-4-hydroxy)-o-phenylpropionic acid, MP 151° to 153°C, was obtained. The melting point of the dimethylaminoethanol salt of unresolved /3-(3,5-diiodo-4-hydroxy)-o-phenylpropionic acid was 142° to 144°C. 

Burlingame R, PJ Chapman (1983) Catabolism of phenylpropionic acid and its 3-hydroxy derivative by Escherichia coli. J Bacteriol 155 113-121. 

Schwarz et al. in agreement with Shukla observed the formation of 2-Oxo-l, 2-dihydroquinoline, 8-hydroxy-2-oxo-l, 2-dihydroquinoline, 8-hydroxycoumarin, and 2,3-dihydroxy-phenylpropionic acid were found as intermediates of quinoline transformation by P. fluorescens 3 and P. putida 86 [325], They compared that metabolic pathway with the one obtained for Rhodococcus strain B1 (Fig. 22). This bacterium was unable to yield denitrogenated metabolites (i.e., 2-oxo-l, 2-dihydroquinoline, 6-hydroxy-2-oxo-l, 2-dihydroquinoline, and 5-hydroxy-6-(3-carboxy-3-oxopropenyl)-lH-2-pyridone). 

Fig. 18. Effect of modifying pH on the adsorption amount of modifying reagent and EDA of 2-hydroxy-3-phenylpropionic acid-MRNi. (O) amount of modifying reagent ( ) EDA of MRNi. Modifying condition 0 C. Reaction conditions MAA (neat), 60 C, 80 kg/cm2.

The absorption modes of (S)-3-phenyl-2-hydroxypropionic acid, (S)-3-phenyl-2-aminopropionic acid, and (S)-alanine adsorbed on a nickel plate or RNi were studied by Suetaka s group (71, 72). From the measurement of infrared (IR) dichroism in the reflection spectrum, the molecular orientation of the modifying reagent was deduced. Figures 19-21 show molecular orientations of (S)-2-hydroxy-3-phenylpropionic acid on a nickel plate and (R)-alanines on RNis modified at 5° and 100°C, respectively. 

Chiral sulphoxides, chiral phosphine, oxazolidinones, rerr.-butyl 2-methyl-.l-hydroxy-3-phenylpropionic acid thiocster... 

C9H10O3 (R)-(-)-2-hydroxy-2-phenylpropionic acid 3966-30-1 32,41 1.1490 2 16917 C9H11NO 1-phenyl-1-propanone oxime 2157-50-8 18.00 1.0639 1... 

C9H10O4 3-hydroxy-4,5-dimethoxybenzaldehyde 29865-90-5 20.50 1.1984 2 16943 C9H11N02 3-amino-3-phenylpropionic acid 614-19-7 22.13 1.1160 2... 

C11H1403 3-hydroxy-2,2-dimethyl-3-phenylpropionic acid iethyl-3-ph 22.07 1.0913 2 22405 C11H160 4-isopentyl phenol 1805-61-4 23.00 0.9562 1... 

The anhydride of a-hydroxymereuri-j8-hydroxy-j8-phenylpropionic acid in alkaline solutions only yields mercuric sulphide on long standing with ammonium sulphide but if the j3-hydroxy group be replaced by methoxy, the decomposition takes place immeiately. 

Taxane alkaloids are made up of a terpenoid core and a phenylpropanoid (3-amino acid, joined by an ester bond. They can be classified according to the carbon-carbon connectivity of the terpenoid core and the type of the side-chain. Thus, the diterpenoid core can be of the taxane- (Tables 3-8), 11 (151 )abeotaxane-(Table 10), 2(3->20)abeotaxane-(Table 2) or 3-11-cyclotaxane (Table 9) type, whereas the side chain can be Winterstein s add [L(R) (3-dimethylamino-P-phenylpropionic add] or N, A/-dimethylphenylisoserine (2R, 3S (threo) a-hydroxy-3-dimethylamino-P-phenylpropionic acid). Further modification occurs in the... 

Methyl-2-hydroxy-3-phenylpropionamide (179 mg, 1 mmol) was refluxed in hydrochloric acid (6 N, 29 ml) for 3 h to give, after extraction witli EtOAc and column chromatography using a silica gel column with a mixture of petroleum ether and EtOAc (1 2) as an eluent, 2 -(+)-2-methyl-2-hydroxy-3-phenylpropionic acid as a white solid (166 mg, 92%). 

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