Efficient, scalable kinetic resolution of cis-4-benzyloxy-2,3-epoxybutanol

A new enzyme catalysed kinetic resolution of cis-4-benzyloxy-2,3-epoxybutanol has been reported. Efficient, scalable separation of the optically active alcohol from its ester derivative has been solved with liquid–liquid and solid–liquid extraction methods using commercial organic solvents and supercritical carbon dioxide. cis-4-Benzyloxy-2,3-epoxy-1-butanol enantiomers were applied for the enantioselective synthesis of (2S,3S,1′S)- and (2R,3R,1′R)-3-[2′-(dibenzylamino)-1′-hydroxyethyl]-2-phenyloxetane.

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(2R,3S)-4-Benzyloxy-2,3-epoxybutanolC11H14O3Ee = 97%[α]D = +23.0 (c 2.4, CHCl3)Source of chirality: enzymatic resolutionAbsolute configuration: (2R,3S)

(2S,3R)-1-Benzyloxy-2,3-epoxybutyl acetateC13H16O4Ee = 71%[α]D = −12.4 (c 2.2, CHCl3)Source of chirality: enzyme catalysed acylationAbsolute configuration: (2S,3R)

(2S,3R)-1-Benzyloxy-2,3-epoxybutyl propionateC14H18O4Ee = 52%[α]D = −10.8 (c 2.0, CHCl3)Source of chirality: enzyme catalysed acylationAbsolute configuration: (2S,3R)

(2S,3R)-1-Benzyloxy-2,3-epoxybutyl butyrateC15H20O4Ee = 54%[α]D = −12.3 (c 2.0, CHCl3)Source of chirality: enzyme catalysed acylationAbsolute configuration: (2S,3R)

(2S,3R)-4-Benzyloxy-1-dibenzylamino-2,3-epoxybutaneC25H25NO2Ee = 99%[α]D = −20.0 (c 2.2, CHCl3)Source of chirality: enantioselective synthesisAbsolute configuration: (2S,3R)

(2R,3R,1′R)-3-[2′-(Dibenzylamino)-1′-hydroxyethyl]-2-phenyloxetaneC25H25NO2Ee = 99%[α]D = −37.7 (c 2.1, CHCl3)Source of chirality: enantioselective synthesisAbsolute configuration: (2R,3R,1′R)