The mode of bakers' yeast transformation of 3-chloropropiophenone and related ketones. Synthesis of (2S)-[2-2H]propiophenone, (R)-fluoxetine, and (R)- and (S)-fenfluramine
作者:Giovanni Fronza、Claudio Fuganti、Piero Grasselli、Andrea Mele
DOI:10.1021/jo00021a011
日期:1991.10
Yeast treatment of 3-chloropropiophenone (2) affords the expected (1S)-3-chloro-1-phenylpropan-1-ol (3) as well as ca. 30% of propiophenone (5). The conversion of 2 into 5 is accompanied by formal elimination of hydrochloric acid, followed by yeast saturation of the double bond of the intermediate phenyl vinyl ketone (4). Monodeuteriopropiophenone formed via yeast treatment from alpha,alpha-dideuterio-3-chloropropiophenone (8) was shown to possess the 2S configuration 10 by conversion into [2-H-2]-(1R,2S)-1-phenylpropan-1-ol (13), whose stereochemistry was assigned by comparison of its NMR properties with those of the [2-H-2]-(1S,2S) diastereoisomer 19 synthesized from yeast-generated (1R,2S)-1-phenylpropane-1,2-diol (15). Whereas product 3 is converted into (R)-fluoxetine (31), 2S alcohol 24, obtained in the yeast reduction of the ketone 22 is transformed into (R)-fenfluramine (29) and into its enantiomer (26).