title: Synthesis and biological evaluation of an electronically activated isooxacephem.
abstract: New isooxacephem (+/-)-3-ethyl 2-hydrogen (6RS,7RS)-8-oxo-7-(phenylacetamido)-4-oxa-1-azabicyclo [4.2.0]oct-2-ene-2, 3-dicarboxylate (8) was synthesized from (+/-)-dibenzyl 2-[cis-2-oxo-3-(phenylacetamido)-4-styryl-1-azetidinyl]-2-[t- butyldimethylsiloxy(methoxycarbonyl)methyl]malonate (1) in six steps. This bicyclic beta-lactam was found to possess notable biological activities against several pathogenic microorganisms in vitro, including Staphylococcus aureus 95, S. aureus FDA 209P, Escherichia coli ATCC 39188, Salmonella typhi O-901, Pseudomonas aeruginosa 18S-H, P. aeruginosa 1101-75, and Klebsiella pneumoniae NCTC 418. The electronic activation of the beta-lactam moiety by an ester group plays a prominent role in the biological activity of this novel isooxacephem.
authors.affiliation: Organosilicon and Synthesis Laboratory, Institute of Chemistry, Academia Sinica, Taipei, Taiwan, R.O.C.
authors.forename: G H
authors.initials: GH
authors.lastname: Hakimelahi
authors.forename: S C
authors.initials: SC
authors.lastname: Tsay
authors.forename: H H
authors.initials: HH
authors.lastname: Tso
authors.forename: Z
authors.initials: Z
authors.lastname: Ramezani
authors.forename: J R
authors.initials: JR
authors.lastname: Hwu
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002511:Cephalosporins / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; C057304:L 656575