| abstract |
Compounds of formula (I) and salts, esters and lactones (where Y=OH) thereof are new: (R4=H or acyl; B=H, CH3, CH3O, or SR; R=aryl or lower alkyl; Y=-CH(A)R5 or is R'; R5=1-3C alkyl; A=H, halo, opt. substd. OH or SH, N3, CN, opt. substd. amino, acyloxy, opt. substd. carbamoyloxy or quaternary ammonium; R'= opt. substd. phenyl or heterocyclyl). Intermediates of formulae (II), (III), (IV), (V) and (VI) are also new: (R1= blocking gp., B'=B other than H; B"=H). (I) are antibiotics active against gram positive and negative bacteria; (II)-(VI) are intermediates to (I). They are used in human or veterinary medicine, as animal feed additives, disinfectants etc. gave dl-3-(1-acetoxy-ethyl)-7beta-(2-thienylacetamido)-3-cephem-4-carb- oxylic acid. |