Novel antibiotic analogues of cephalosporins

摘要: Novel antibiotics of the formula: ##STR1## and its salts, esters amides wherein R is acyl; B H, OMe, Me or SR lower alkyl aryl; A1 hydrogen, hydroxy, an organic group; and, X a divalent radical selected from --O--, --CH2 --, --NY-- where Y hydrogen 1 to 6 carbon atoms such as methyl, ethyl, i-propyl, n-butyl, n-pentyl, n-hexyl like, formyl benzyl. This invention directed novel antibiotics, intermediates useful in their preparation, processes for preparing antibiotics. The are effective against gram-negative bacteria including Proteus vulgaris, E. coli Salmonella schottmulleri, gram-positive Staphylococcus aureus Bacillus subtilis combatting bacterial infections animals humans addition various industrial applications.