L-Phenoxy-2-propanone

Figure 9. Acetophenone-mediated electroenzymatic reduction of l-phenoxy-2-propanone to (5 )-1 -phenoxy-2-propanol using lipoamide dehydrogenase (LiDH) or ferredoxin-NADP reductase (FNR) and an alcohol dehydrogenase [46].

Dealing with substrate inhibition caused by application of higher amounts of reachon educts needs further investigahons in terms of ideal reaction conditions and amino donor/acceptor ratio. One crucial step for successful transamination is the choice of a suitable amino donor. Fesko et al. evaluated the influence of several amino donors and substrates to investigate a one-enzyme system [41], The influence of the amino donor on the ee was shown by examination of reactions catalyzed by the co-transaminase from Paracoccus denitrificans. Usually low ee values were obtained with alanine as the amino donor. The best results were acquired with l-phenoxy-2-propanone and 1-phenylethylamine in sodium phosphate buffer pH 7.5 at 30 °C. To get higher substrate loading, it is necessary to add cosolvents due to the low solubility of the substrates. In this study, cyclohexane and sodium dodecyl sulfate (SDS) were best cosolvents. For the preparation of (R)- and (S)-phenoxypropane-2-amine in a similar yield, three enzymes were used for the synthesis [66] rac-2-butylamine as amino donor usage was increased by tenfold (500 mM). 

The collected ethereal filtrates were acidified with 50 ml of 4 N hydrochloric acid and this solution was stirred vigorously. The hydrochloride of l-(4 -benzyloxyphenyl)-2-(l,-methyl-2-phenoxy-ethylamino)propanone-l precipitated out, was filtered off, washed with water and then with diethyl ether. Then this substance was dried in vacuo. The yield was 37.7 g, i.e., 89% of the theoretically possible yield, calculated on l-(4 -benzyloxyphenyl)-2-bromine propanone-1. This substance had a light yellow color and melted at 197 to 198°C, while decomposing. 

Hydroxy-3-methoxy-5-[2-methoxy-4-(l-oxopropyl)phenoxy] phenyl]-l-propanone... 

Dimethoxy-2-(l-oxopropyl)phenoxy]propanoic acid ethyl ester, 1938 1 -(4-Hydroxy-3-methoxyphenyl)-1 -propanone (P-D-Glucopyranoside), 1817... 

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