| abstract |
beta -Lactam antibiotics are disclosed which have the formula (IA) or pharmaceutically acceptable salts or pharmaceutically acceptable in vivo hydrolyzable esters thereof: <IMAGE> (IA) wherein R1 is phenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, 3-aminophenyl, 4-aminophenyl, or 3,4-dihydroxyphenyl, the hydroxy and amino groups being optionally protected, and R is C1-8 alkyl; and also the use thereof. Processes for the preparation of the compounds are disclosed together with intermediates for use therein. |