Abstract: Chromogenic or fluorescent carbapenems according to formula I, wherein Ar is a mono or disubstituted carbocyclic aromatic group or an optionally mono or disubstituted heterocyclic aromatic group, are useful compounds for the detection of bacterial carbapenemase.

Abstract: Chromogenic or fluorescent carbapenems according to formula I, wherein Ar is a mono or disubstituted carbocyclic aromatic group or an optionally mono or disubstituted heterocyclic aromatic group, are useful compounds for the detection of bacterial carbapenemase.

Abstract: Novel tumour selective anti-neoplastic agents are characterized, in that to customary antineoplastic agents are attached one or two very specific unbranched &OHgr;-hydroxyalkyl, (&OHgr;-hydroxy)alkenyl, &OHgr;-(2,3-dihydroxypropyloxy)alkyl or an (&OHgr;-(2,3-dihydroxypropyloxy))alkenyl groups R2 and R3 with 5 to 30 carbon atoms, forming a tumour selective conjugate as exemplified with the compounds of formulae I, II and III [] wherein R1 is a customary pharmaceutically acceptable inorganic or organic leaving group and A is 1,2-dimethylene, 1,3-trim ethylene, 1,2-cyclopentylene or 1,2-cyclohexylene.

Abstract: The compounds of the general formula (I) wherein R1 denotes a pharmaceutically acceptable side chain radical as used conventionally in the field of cephalosporins and wherein R2 denotes a pharmaceutically acceptable group which is bonded to the remaining part of the molecule by an oxygen-carbon single bond or a nitrogen-carbon single bond, and their pharmaceutically acceptable salts, esters and amide derivatives are effective antibiotics.

Abstract: Compounds of the structural formulae ##STR1## and their pharmaceutically acceptable salts, esters and amide derivatives, in which R.sup.1 and R.sup.2, independently of one another, denote hydrogen or pharmaceutically acceptable groups which have 1 to 10 carbon atoms and are bonded to the remaining part of the molecule via carbon-carbon single bonds, and in which R.sup.3, R.sup.4 and R.sup.5, independently of one another, denote pharmaceutically acceptable groups which have 1 to 10 carbon atoms and are bonded to the remaining part of the molecule via carbon-carbon single bonds, are useful antibiotics.The trisubstitution by three groups R.sup.3, R.sup.4 and R.sup.5, which are bonded via carbon-carbon single bonds, results in a noticeable increase in the hydrolysis stability and thus also in the antibacterial action of axapenemcarboxylic acids.

Abstract: Novel process for the preparation of azetidin-2-ones of the formula ##STR1## wherein R.sup.1 and R.sup.2 independently from each other are hydrogen, or an organic group linked to the ring carbon via a carbon atom, a nitrogen atom or an oxygen atom, characterized in that a corresponding 4-acyloxyazetidin-2-one, which is substituted by a group --O--CO--R.sup.3 at the 4-position, wherein R.sup.3 is hydrogen or an organic radical stable at the reaction conditions, is reacted with a complex metal hydride comprising reactive hydride ions, such as, lithium borohydride, sodium borohydride, potassium borohydride, zinc borohydride or tetraorganoammonium borohydride.

Abstract: Subject of the present invention are compounds of the formula ##STR1## which can be used as intermediates, wherein R represents hydrogen or R.sub.a, which represents an organic radical bonded to the ring carbon atom via a carbon atom,each of the radicalsR.sub.b and R.sub.c represents hydrogen or an organic radical bonded to the ring carbon atom via a carbon atom, it being possible for the two radicals to be bonded to one another,A represents a lower alkylene radical having 2 or 3 carbon atoms between the two hetero atoms, andn represents 0 or 2,the stereoisomers thereof and mixtures of these stereoisomers and also processes for the manufacture of such compounds of the formula I.From compounds of the formula I it is possible to manufacture 6-R.sub.a -2-penem-4-carboxylic acid compounds having antibiotic properties.