| 摘要 |
Antibacterially active and animal feedstuff supplement beta -lactam antibiotics of the formula <IMAGE> (I) in which R is H or -UR', U is O or S, R' is optionally substituted alkyl, alkenyl, alkinyl, aralkyl, aryl or cycloalkyl, <IMAGE> R1 and R2 individually are hydrogen or, individually or together with the carbon atom to which they are bonded, are any of various radicals, A is -CH2-CH2-, -CH2-CH2-CH2- or <IMAGE> B is optionally substituted phenyl or is cyclohexenyl or cyclohexadienyl; X is S, O, SO, SO2 or -CH2-; and Y is a group of the formula <IMAGE> T is hydrogen, alkyl-CO-O-, pyridinium, aminopyridinium, carbamoyloxy, azido, cyano, hydroxyl or optionally substituted -S-phenyl, or is -S-Het, in which Het is an optionally substituted heterocyclic 5-membered or 6-membered ring; and wherein E is hydrogen, a radical forming, with the carboxyl group to which it is attached, a carboxy ester group, a cation of a salt, or a protective group, or a hydrate thereof. A process is also given for converting R directly from H to UR' employing a base, a halogenating agent and R'UH. |
