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Preparation of isoxazolidinyl nucleoside enantiomers by lipase-catalysed kinetic resolution
- Source :
-
Tetrahedron: Asymmetry . Mar2009, Vol. 20 Issue 4, p425-429. 5p. - Publication Year :
- 2009
-
Abstract
- Abstract: An efficient biocatalytic procedure to obtain chiral N,O-nucleoside derivatives consisting of a lipase-catalysed resolution of the corresponding racemates in organic solvent has been developed. Enantioselective esterification of thymine and cytosine derivatives, (±)-9a and (±)-9b, has been investigated by comparing the efficiency of different lipases and acyl donors. Since esterification of (±)-9a and (±)-9b, occurred with low enantioselectivity (E ⩽14) in the presence of the lipases considered, for preparative purposes we resorted, with success, to a double sequential kinetic resolution, using Lipozyme IM as the best catalyst. This approach enables us to obtain all the enantiomers with ee⩾95%. The absolute configuration of the new chiral N-acetyl cytosine derivative 9b was established by circular dichroism spectroscopy. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 09574166
- Volume :
- 20
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- Tetrahedron: Asymmetry
- Publication Type :
- Academic Journal
- Accession number :
- 37347674
- Full Text :
- https://doi.org/10.1016/j.tetasy.2009.02.026