A novel synthetic approach to N-unsubstituted β-lactams

✍ Scribed by Fernando P Cossío; Claudio Palomo

• Publisher: Elsevier Science
• Year: 1985
• Tongue: French
• Weight: 269 KB
• Volume: 26
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)99001-4

✦ Synopsis

A convenient simple route to N-unsubstituted B-lactams is described. Formation of unusual N-styryl--B-lactams is the key of the method. Synthesis of N-unsubstituted B-lactams have received increased attention in the past few years and specially with the advent of the third generation of 8-lactam antibiotics'. We have been interested, therefore, in converting easily synthesized monocyclic 6-lactams to the corresponding N-unsubstituted derivatives. Manhas and Bose' have reported that permanganate oxidation of 6-lactams of type 1 give the corresponding 4-carboxy--azetidinones 2. We expected that under the same conditions 6-lac-RL.Ph RbR2 tams 3 afforded the N-unsubstituted B-lactams 2. Unfortunately, the direct disconnection approach of these 8-lactams 2 leads to an unusual CrN+Ph synthon, the vinylamine 9 (Analysis 1). However, we have found that by means of a simple functional group interconversion, (Analysis 21,