Chemoenzymatic synthesis of chiral epoxides. Preparation of 4-phenyl-2,3-epoxybutane and 1-phenyl-1,2-epoxypropane
摘要:
All the stereoisomers of 4-phenyl-2,3-epoxybutane and 1-phenyl-1,2-epoxypropane (beta-methylstyrene oxide) have been prepared in three steps from 4-phenyl-2-butanone and 1-phenyl-2-propanone or 1-phenyl-1-propanone respectively. The key step is the microbiological reduction of the corresponding haloketones. These results confirm those previously described(1) and demonstrate that the chemoenzymatic synthesis of homochiral 2,3-epoxides is a general method that can be used whatever the starting ketone.
Non-Racemic Halohydrinsvia Biocatalytic Hydrogen-Transfer Reduction of Halo-Ketones and One-Pot Cascade Reaction to Enantiopure Epoxides
作者:Tina M. Poessl、Birgit Kosjek、Ursula Ellmer、Christian C. Gruber、Klaus Edegger、Kurt Faber、Petra Hildebrandt、Uwe T. Bornscheuer、Wolfgang Kroutil
DOI:10.1002/adsc.200505094
日期:2005.11
possibility for a follow-up reaction of halohydrins is the ring closure to the corresponding epoxide. A novel “one pot-one step strategy” was employed to obtain the enantiopureepoxide from the α-chloro-ketone in a cascade like fashion at pH>12 involving biocatalytic hydrogen transfer reduction and in situ chemo-catalyzed ring closure.