The intramolecular aromatic nucleophilic substitution as a route to tricyclic β-lactams. Synthesis of the novel 4-oxa-7-azabicyclo[4.2.0]octane skeleton
2003; Elsevier BV; Volume: 59; Issue: 28 Linguagem: Inglês
10.1016/s0040-4020(03)00778-6
ISSN1464-5416
AutoresPaola Del Buttero, Giorgio Molteni, Antonio Papagni, Tullio Pilati,
Tópico(s)Synthesis and Biological Activity
ResumoSodium borohydride-carbonyl reduction of the novel 3-(2-fluoro-5-nitro) phenyl-4-benzoyl-2-azetidinones 3 and 7 gave quantitatively the stereoisomeric carbinols (4R p ,5S p )-4 and (4R p ,5R p )-5. Treatment of the latter with sodium hydride gave the title compounds 8 and 9, respectively, with good overall yield. The rationale of the stereochemical relationships outlined in the sequences 3 (or 7)!4!8 and 3 (or 7)!5!9 is given according to the conformational and keto-enol equilibria of the reactant(s). q 2003 Elsevier Science Ltd. All rights reserved.
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