title: Assignment of the C-5 configuration of penicilloic acids.
abstract: Penicilloates prepared by the method of Munro et al (1978) were examined by nuclear magnetic resonance spectroscopy and optical rotation to assign the configuration at C-5. The configuration was 5S for carbenicillin and ticarcillin penicilloates and 5R for the other seven penicilloates examined. The chemical shift and coupling constants of 5-H and 6-H showed consistent differences between the isomers and the optical rotation of the 5R-isomers is consistently more positive than that of the corresponding 5S-isomer.
authors.affiliation: Beecham Pharmaceuticals Research Division, Chemotherapeutic Research Centre, Betchworth, Surrey, UK.
authors.forename: A E
authors.initials: AE
authors.lastname: Bird
authors.forename: E A
authors.initials: EA
authors.lastname: Cutmore
mesh_terms: D000658:Amoxicillin / Q000032:analysis; D000667:Ampicillin / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D009905:Optical Rotatory Dispersion; D010397:Penicillanic Acid / Q000032:analysis* / Q000031:analogs & derivatives
chemical_list: C008782:penicilloic acid; D000667:Ampicillin; D000658:Amoxicillin; D010397:Penicillanic Acid