4 3-Phenylpropionaldehyde

Add the salt to dilute hydrochloric acid (prepared from 28 ml. of the concentrated acid and 150 ml. of water) contained in a 500 ml. flask fitted with a reflux condenser. Warm the mixture gently carbon dioxide is evolved and an oil separates. Heat on a steam bath for 90 minutes, cool, and extract the oil with 75 ml. of benzene. Wash the extract with 100 ml. of water, and distil the benzene solution under reduced pressure from a Claisen flask. Collect the a-phenylpropionaldehyde at 90-93°/10 mm. the yield is 30 g. 

Phenylpropionaldehyde (>90%) was purchased from Fluka and was purified by distillation. 

On the other hand, 3-phenylpropionitrile was synthesized from Z-3-phenyl-propionaldoxime (0.75 M) in a quantitative yield (98gP ) by the use of cells of E. coli JM 109/pOxD-9OF, a transformant harboring a gene for a new enzyme, phenylacetaldoxime dehydratase, from Bacillus sp. strain OxB-1. Other arylalkyl- and alkyl-nitriles were also synthesized in high yields from the corresponding aldoximes. Moreover, 3-phenylpropionitrile was successfully synthesized by the recombinant cells in 70 and 100% yields from 0.1 M unpurified P/Z-3-phenylpropionaldoxime, which is spontaneously formed from 3-phenylpropionaldehyde and hydroxylamine in a butyl acetate/water biphasic system and aqueous phase, respectively. 

Another important class of pharmaceuticals which is prepared from chiral 2-hydroxy acids is the angiotensin-converting enzyme (ACE) inhibitors. (R)-3-phenylpropionaldehyde cyanohydrin is transformed into the corresponding 2-hydroxy ester which after activation by sulfonylafion reacts with dipetides to give, under inversion of configuration, ACE inhibitors known as prils (Scheme 6). ... 

Scheme 6 Stereoselective synthesis of ACE inhibitors from 3-phenylpropionaldehyde cyanohydrin.

It has been reported that the geometry of olefins obtained from the reaction of dialkyl l-(ethoxycarbonyl)ethylphosphonates and a-phenylpropionaldehyde can be controlled by choice of the phosphonate ester alkyl groups diisopropyl ester gives (E), while dimethyl ester gives (Z). This has now been confirmed for the... 

Heck C-C coupling reactions were also facilitated by the presence of a palladium catalyst when Pd was deposited on a tubular membrane of porous glass. Thus, the coupling of iodobenzene with allyl alcohol affording 3-phenylpropionaldehyde in the presence of this Pd catalyst had several advantages - the ease of catalyst manufacture, mechanical strength, thermal stability, and resistance to organic solvents [46],... 

The first chiral a-oxygenated stannanes were prepared by Still59. Addition of Bu3SnLi to a-methy l-/J-phenylpropionaldehyde followed by MOMC1 led to a separable 1 1 mixture of syn and anti alkoxy stannanes (Scheme 26). Lithiation with n-BuLi and addition of acetone gave the respective adducts with overall retention of stereochemistry. Thus, it is implied that the intermediate a-alkoxy lithio derivatives retain their configuration. 

Photolytic. Major products reported from the photooxidation of isopropylbenzene with nitrogen oxides include nitric acid and lienzaldehyde (Altshuller, 1983). A / -hexane solution containing isopropylbenzene and spread as a thin film (4 mm) on cold water (10 °C) was irradiated by a mercury medium pressure lamp. In 3 h, 22% of the applied isopropylbenzene photooxidized into a,a-dimethylbenzyl alcohol, 2-phenylpropionaldehyde, and allylbenzene (Moza and Feicht, 1989). 

Phenylpentane, see Propylbenzene Phenylphenol, see 2-Chlorobiphenvl 2-Phenylpropionaldehyde, see Isopropylbenzene Phenylpyruvic acid, see Biphenyl l-Phenyl-3-(l,2,5-thiadiazol-3-yl)urea, see... 

Ahlbrecht and coworkers showed that the stereoselective alkylation of Af-cinnamyl (5 )-2-methoxymethylpyrrolidine (STdR), followed by hydrolysis, affords enantiomerically enriched 3-substituted phenylpropionaldehydes, as shown in Scheme 45. This method is analogous to the asymmetric alkylation of S AMP/RAMP hydrazones, as the anions are isoelectronic. The mechanisms of asymmetric induction for the two systems are probably similar. For the lithio cinnamyl amine, methylation can be optimized up to 97.5% ds. Most of the procedures in this paper include potassium tert-butoxide, so the cation in these examples may be potassium. Under these conditions, methyl, primary and secondary alkyl iodides typically afford the products with selectivities in the 90-93% ds range. 

Phenylmercuric acetate, with meth-allyl alcohol to yield 2-methyl-3-phenylpropionaldehyde, 51,17 l-PHENY L-1,3-PENTADIYNE, 50,... 

ALDEHYDES FROM ALLYLIC ALCOHOLS AND PHENYLPALLADIUM ACETATE 2-METHYL-3-PHENYLPROPIONALDEHYDE... 

Other preparations of 2-methyl-3-phenylpropionaldehyde include the pyrolysis of a mixture of the calcium salts of 2-mothyl-3-phenylpropionie acid and formic acid,3 and the... 

The Jacobsen group independently focussed on the development of primary amine-functionalized thiourea derivatives and published, in 2006, the thioureas 100-103 incorporating the established tert-leucine (amide) motif (Figure 6.14) and the diaminocyclohexane or diphenylethylenediamine chiral backbone, respectively (Figure 6.31) [262]. The catalyst screening was carried out in the asymmetric Michael addition [149-152] of 2-phenylpropionaldehyde, an a,a-disubstituted aldehyde, to 1-nitrohex-l-ene (at 20mol% loading, DCM, rt, variable equiv. of H2O)... 

Figure 6.31 Primary amine-functionalized thioureas screened in the asymmetric Michael addition of 2-phenylpropionaldehyde to 1-nitrohex-l-ene using DCM as the solvent.

Scheme 6.105 Asymmetric Michael addition of phenylpropionaldehyde to trar)s- 3-nitrostyrene catalyzed by primary amine thioureas 102, 104, and 105.

Figure 6.49 Binaphthyl-derived tertiary amine-functionalized bifunctional thiourea derivatives screened in the MBH reaction between 2-cyclohexen-l-one and 3-phenylpropionaldehyde at rt in dichloromethane.

ALKYLATIONS OF ALDEHYDES via REACTION OF THE MACNESIOEN AMINE SALT OF AN ALDEHYDE 2,2-DIMETHYL-3-PHENYLPROPIONALDEHYDE... 

Mixed aldehydes yielded similar condensation products. For example, excess benzaldehyde reacted with acetaldehyde to form a-benzylcirmamaldehyde presumably, cinnamaldehyde and phenylpropionaldehyde were intermediates. Cinnamaldehyde itself yielded a-benzylphenylpentenal. 

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