| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1347337 | Tetrahedron: Asymmetry | 2009 | 6 Pages |
Epoxidation of alkenes by peracid, generated in situ from (2R,3S,4R,5S)-(−)-2,3:4,6-di-O-isopropylidiene-2-keto-l-gulonic acid monohydrate [(−)-DIKGA] and hydrogen peroxide by lipase catalysis induces chirality on the product epoxides with moderate to good enantioselectivity (35–71%). Alkoxy/aralkyloxy styrenes however did not undergo any epoxidation. (R)-(+)-4-Hydroxy styrene-7,8-oxide was formed and isolated with moderate enantiomeric excess (57%) but was found to have poor stability.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide
(R)-(+)-PhenyloxiraneC8H8OEe = 46%[α]D22=+21.5 (c 0.8, PhH)Source of chirality: chiral catalystAbsolute configuration: (R)
(R)-(+)-4-HydroxyphenyloxiraneC8H8O2Ee = 57%[α]D25=+4.95 (c 0.8, CHCl3)Source of chirality: chiral catalystAbsolute configuration: (R)
(R)-(−)-(4-Chlorophenyl) oxiraneC8H7OClEe = 46%[α]D22=-11.5 (c 0.65, CHCl3)Source of chirality: chiral catalystAbsolute configuration: (R)
(R)-(−)-(3-Nitrophenyl) oxiraneC8H7NO3Ee = 63%[α]D20=-1.6 (c 2.1, CHCl3)Source of chirality: chiral catalystAbsolute configuration: (R)
(R)-(−)-(2-Nitrophenyl) oxiraneC8H7NO3Ee = 68%[α]D19.5=-72.9 (c 1.20, CHCl3)Source of chirality: chiral catalystAbsolute configuration: (R)
(2R,3R)-Epoxybutan-1-olC4H8O2Ee = 35%[α]D25=+19.3 (c 0.05, CHCl3)Source of chirality: chiral catalystAbsolute configuration: (2R,3R)
(2R,3R)-Epoxy-2-methylpentan-1-olC6H12O2Ee = 71%[α]D25=+4.3 (c 0.03, CHCl3)Source of chirality: chiral catalystAbsolute configuration: (2R,3R)
