Enzymatic resolution of ethyl 3-hydroxy-2(1′substituted-methylidene)-butyrate by Pseudomonas cepacia lipase catalyzed acetylation

Enzymatic resolution of a series of enantiomerically pure ethyl 3-hydroxy-2(1′substituted-methylidene)-butyrates was performed using Pseudomonas cepacia lipase (EC 3.1.1.3) as a catalyst. Optically active ethyl 3-hydroxy-2(1′substituted-methylidene)-butyrates, as well as their acetates, were obtained from this reaction in good yield and excellent enantiomeric excess.

Figure optionsDownload as PowerPoint slide

(3S)-Ethyl 3-hydroxy-2(1′-isopropyl-methylidene)-butyrateC10H18O3Ee >99%[α]D25=-11.0 (c 1.0, CHCl3)Source of chirality: lipase catalyzed kinetic resolutionAbsolute configuration: (S)

(3S)-Ethyl 3-hydroxy-2(1′-cyclohexyl-methylidene)-butyrateC13H22O3Ee = 88%[α]D25=-8.7 (c 1.0, CHCl3)Source of chirality: lipase catalyzed kinetic resolutionAbsolute configuration: (S)

(3S)-Ethyl 3-hydroxy-2[1′(4-methoxy-phenyl)-methylidene]-butyrateC14H18O4Ee >99%[α]D25=-4.0 (c 1.0, CHCl3)Source of chirality: lipase catalyzed kinetic resolutionAbsolute configuration: (S)

(3R)-Ethyl 3-acetoxy-2(1′-isopropyl-methylidene)-butyrateC12H20O4Ee >99%[α]D25=+36.5 (c 1.0, CHCl3)Source of chirality: lipase catalyzed kinetic resolutionAbsolute configuration: (R)

(3R)-Ethyl 3-acetoxy-2(1′-cyclohexyl-methylidene)-butyrateC15H24O4Ee >99%[α]D25=+27.2 (c 1.0, CHCl3)Source of chirality: lipase catalyzed kinetic resolutionAbsolute configuration: (R)

(3R)-Ethyl 3-acetoxy-2[1′(4-methoxy-phenyl)-methylidene]-butyrateC16H20O5Ee >99%[α]D25=+44.3 (c 1.0, CHCl3)Source of chirality: lipase catalyzed kinetic resolutionAbsolute configuration: (R)