352438-07-4Relevant academic research and scientific papers
New Routes to Chiral Evans Auxiliaries by Enzymatic Desymmetrisation and Resolution Strategies
Neri, Claudia,Williams, Jonathan M. J.
, p. 835 - 848 (2007/10/03)
This paper describes how enantiomerically enriched Evans auxiliaries can be successfully prepared by either an enzymatic desymmetrisation strategy or an asymmetric synthesis using racemic auxiliaries and an enzymatic resolution. Desymmetrisation of N-Boc-protected serinol has been achieved in good yield and high enantiomeric excess using porcine pancreas lipase. This has been exploited in different ways to prepare enantiomerically enriched (4R)- and (4S)-substituted 2-oxazolidinones. In another approach to asymmetric synthesis, starting from a racemic Evans auxiliary, by means of a diastereoselective aldol reaction coupled with a lipase-catalysed resolution, we achieved the preparation of enantiomerically enriched β-hydroxy acids and enantiomerically enriched 2-oxazolidinones.
Racemic auxiliaries: Applications to asymmetric synthesis
Neri, Claudia,Williams, Jonathan M.J.
, p. 4257 - 4260 (2007/10/03)
Racemic auxiliaries have been successfully used to achieve asymmetric synthesis. Racemic Evans aldol products were obtained from racemic acyl oxazolidinones with good diastereocontrol. The enantiomers of the racemic aldol products were resolved by a lipase-catalysed acylation reaction. Hydrolysis afforded enantiomerically enriched oxazolidinones and enantiomerically enriched β-hydroxy acids.
