Stereoselective Synthesis of β‐Lactams by Using D‐Mannitol‐Derived Oxazolidin‐2‐one as a Chiral Auxiliary

Abstract

Chiral oxazolidin‐2‐ones containing isopropylidene and cyclohexylidene functionalities, readily available from D‐mannitol, have been demonstrated to undergo highly diastereoselective β‐lactam synthesis via the Staudinger reaction with Mukaiyama reagent. Stereoselectivity for cis‐β‐lactam was the result of the [2 + 2] cycloaddition reaction of ketene to trans imines, and cyclohexylidene showed better yield and stereoselectivity than the isopropylidene auxiliary.

Keywords:

• β‐Lactam
• D‐mannitol
• Mukaiyama reagent
• oxazolidine‐2‐one
• Staudinger reaction

Acknowledgment

This research was supported by the Korea Science and Engineering Foundation (RRC) through the Silver Biotechnology Research Center at Hallym University, and by Hallym University Research Fund 2004 (HRF‐2004‐29).