METAL-CATALYZED AND METAL-PROMOTED CYCLIZATIONS FOR THE SYNTHESIS OF CEPHALOSPORINS - A POSSIBLE DAOC DAC SYNTHETASE BIOMIMETIC PROCESS/

Authors
CABRI W BORGHI D ARLANDINI E SBRALETTA P BEDESCHI A
Citation
W. Cabri et al., METAL-CATALYZED AND METAL-PROMOTED CYCLIZATIONS FOR THE SYNTHESIS OF CEPHALOSPORINS - A POSSIBLE DAOC DAC SYNTHETASE BIOMIMETIC PROCESS/, Tetrahedron, 49(31), 1993, pp. 6837-6848
Citations number
29
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Tetrahedron → ACNP
ISSN journal
00404020
Volume
49
Issue
31
Year of publication
1993
Pages
6837 - 6848
Database
ISI
SICI code
0040-4020(1993)49:31<6837:MAMCFT>2.0.ZU;2-A
Abstract
A thiyl radical cyclization approach to the sulphur containing ring of cephams is described. The reaction was carried out using metals able to perform a single-electron oxidation process under stoichiometric [F e(III), Mn(OAc)3] or catalytic [Fe(III)] conditions. Furthermore, the FeCl3 or Mn(OAc)3/LiX promoted reactions afforded, by a double single- electron oxidation process, over oxidized compounds The relationship w ith the mechanistic hypothesis proposed by Baldwin for the DAOC/DACS-c atalyzed ring expansion from Penicillin N to Desacetoxy cephalosporin C is discussed.