D-xylose derived oxazolidin-2-ones as chiral auxiliaries in stereoselective acylations and halogenations

✍ Scribed by Arne Lützen; Peter Köll

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 252 KB
• Volume: 8
• Category: Article
• ISSN: 0957-4166
• DOI: 10.1016/s0957-4166(96)00478-8

✦ Synopsis

Chiral N-acylated oxazolidin-2-ones readily available from D-xylose have been demonstrated to undergo highly diastereoselective acylation reactions via their lithium imide enolates to afford 13-keto imides. These are easily purified and exhibit surprisingly high stability towards epimerization. The glyco-oxazolidin-2-ones can also be used in diastereoselective halogenation reactions via their boron enolates to get et-halogenated products.These and the branched N-acyl compounds can be hydrolyzed allowing isolation of the desired halogenated and ramified carboxylic acids and return of the auxiliaries for reuse. (~