Baker's yeast reduction of (E)-1-phenyl-1,2-propanedione 2-(O-methyloxime). A key step for a (-)-norephedrine synthesis

Article abstract of DOI:10.1016/S0957-4166(97)00280-2

The enantioselective Baker's yeast reduction of (E)-1-phenyl-1,2-propanedione 2-(O-methyloxime) 1 afforded (-)-(R)-1-hydroxy-1-phenyl-2-propanone 2-(O-methyloxime) 2 with 97% of enantiomeric excess (ee) which was diastereoselectively reduced by LiAlH₄ to obtain the (-)-(R,S)-norephedrine with ee=82% and (-)-(R,R)-norpseudoephedrine with ee=93% in a ratio 4:1 respectively.