| Autor: |
I. F. Fernandez, M. S. Khajavi, L. Mukkavilli, K. Gala, Ajay K. Bose, B. Ram, J. E. Vincent, M. Sugiura, Maghar S. Manhas, R. Gruska, S. G. Amin, J. C. Kapur, J. Kreder, J. M. Van Der Veen |
| Rok vydání: |
1981 |
| Předmět: |
|
| Zdroj: |
Tetrahedron. 37:2321-2334 |
| ISSN: |
0040-4020 |
| Popis: |
A safe and convenient method is described for the synthesis of α-amido-β-lactams starting with glycine and an azomethine. The amino group of glycine is protected by reaction with a β-dicarbonyl compound following the method of Dane et al. and the carboxyl group is activated through the formation of a mixed anhydride or an active ester. Condensation between these glycine derivatives and acyclic or cyclic imino compounds (including thioimidates) in presence of triethylamine leads to stereospecific synthesis of 3-(β-carbonyl-vinylamino)-2-azetidinones in 40–60% yield. The vinylamino side chain can be hydrolyzed under mild acid conditions to form 3-amino-2-azetidinones which can be acylated to α-amido-β-lactams. Alternatively, the vinylamino side chain can be converted to an amido side chain by ozonolysis. The molecular parameters of a 3-(β-carbonyl-vinylamino)-2-azetidinone were determined by X-ray crystallography. Usefulness of this α-amido-β-lactam synthesis is illustrated by the preparation of isotopelabeled β-lactams and intermediates for some β-lactam antibiotics. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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