Enantioselective bioreduction of ( E )-1-phenyl-1,2-alkanedione 2-( O- methyloxime)
摘要:
The baker's yeast reduction of (E)-1-phenyI-1,2-alkanedione 2-(O-methyloxime), PhC(O)C(NOMe)R (R = Me, Et, n-Pr, n-Bu), gave the corresponding optically active alcohols PhCH2OHC(NOMe)R in 88-99% enantiomeric excess and 48-75% chemical yield. The R configuration was proposed for these alcohols based on circular dichroism analysis. Only the phenylglyoxal O-methylaldoxime (R=H) gave poor enantiomeric excess (65%) and chemical yield (14%). These compounds are potential chiral building blocks for the stereoselective synthesis of norephedrine analogs. (C) 2000 Elsevier Science Ltd. All rights reserved.
Henry reaction of in situ generated nitrosocarbonyl intermediates and concomitant denitration cascade has been developed. The reaction is catalyzed by organic base at room temperature offering α-ketoamides, a demanding scaffold for drug discovery, in high yields. An alteration of substitution pattern also produced α-keto oximes, a high-value synthon. The protocol features operational simplicity and broad