Download PDF
Synlett 1990; 1990(7): 431-432
DOI: 10.1055/s-1990-21119
letter
© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

Synthesis of Azetidinones from L-Threonine: Formation of Unusually Stable Bicyclic Hemiketals and cis-Azetidinones

M. Kugelman* , D. Gala, R. S. Jaret, P. L. Nyce, A. T. McPhail
  • *Process Research and Development, Schering Plough Corporation, Bloomfield, NJ 07003, USA
Further Information

Publication History

Publication Date:
08 March 2002 (online)

  PDF Download  Permissions and Reprints All articles of this category

L-Threonine-based synthesis of azetidinones/penems leads to the desired trans-azetidinones as well as novel, unusually stable bicyclic hemiketals/cis-azetidinones. The latter compounds are resistant to Baeyer-Villiger oxidation, and hence they can not be used towards penem synthesis. Structures of the bicyclic hemiketal, (1S,2R, 4R,5R)-4-(4-chlorophenyl)-4-hydroxy-6-(4-methoxyphenyl)-2-methyl-3-oxa-6-azabicyclo[3.2.0]heptan-7-one, and the cis-azetidione, (3S, 4R)-3-[(R)-1-(acetoxy)ethyl]-4-(4-chlorobenzoyl)-1-(4-methoxyphenyl)-2-azetidinone, were established by x-ray crystallography.