The Synthesis of Novel Cyclic β-Amino Acids as Intermediates for the Preparation of Bicyclic β-Lactams

✍ Scribed by Wolfgang Maison; Marc Kosten; Audrey Charpy; Jürgen Kintscher-Langenhagen; Imre Schlemminger; Arne Lützen; Ole Westerhoff; Jürgen Martens

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 316 KB
• Volume: 1999
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(199909)1999:9<2433::aid-ejoc2433>3.0.co;2-x

✦ Synopsis

Several derivatives of homopipecolic acid are prepared by αthiazolidineacetic acids by epimerisation experiments. A method for resolution of the obtained racemic β-amino acids amino alkylation of malonic acid with cyclic imines 6 and 7. These are prepared on a large scale and with different by diastereomeric salt formation is described. The β-amino acids 9 and 15 were converted into their corresponding substitution patterns. The β-amino acids 8 and 9 were formed in high yield and with remarkable diastereoselectivity if carbacepham analogues 14 and isopenam 16. The isopenam endo-16 was selectively epimerised by mild basic treatment chiral imines are used as starting materials. The diastereoselectivity of the amino alkylation leading to of the N/S-acetal to give an exo-configured precursor of isopenicillin G. homopipecolic acid analogues is compared to those of Herein we report on an efficient synthesis of previously tion also worked well for a number of heterocyclic imines 26111 Oldenburg, Germany