| 摘要 |
Process for N-acyloxy or sulfooxy 2-azetidinones comprising O-acylation of a .beta.-hydroxy or .beta.-halo hydroxamic acid, and cyclizing the O-acylhydroxamate with TPP-CCl4-TEA or with TPP-dialkylazodicarboxylate to the N-acyloxy-2-azetidinone. Solvolysis of the acyl group provides an N-hydroxy-2-azetidinone. E.g., N-Cbz-L-serine is converted to the O-acetyl hydroxamate, cyclized and solvolyzed to N-hydroxy-3-(Cbz-amino)-2-azetidinone. The N-hydroxy-2-azetidinones are useful intermediates to monocyclic .beta.-lactam antibiotics and .beta.lactamase inhibitors.
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