Abstract: The manufacture of 1-sulpho-2-oxazetidine derivatives of the formula ##STR1## in which Het is an optionally amino-substituted, 5- or 6-membered, aromatic heterocycle containing 1 or 2 nitrogen atoms and optionally also an oxygen or sulphur atom, R.sup.1 is hydrogen, lower alkyl, phenyl-lower alkyl, lower alkanoyl, lower alkoxycarbonyl, lower alkenyl-lower alkyl, lower alkoxycarbonyl-lower alkyl, phenyl-lower-alkoxycarbonyl-lower alkyl, nitrophenyl-lower-alkoxycarbonyl-lower alkyl or carboxy-lower alkyl and R.sup.2 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, lower alkoxycarbonyl, lower alkanoyloxy-lower alkyl, lower alkoxycarbonyl-lower alkenyl, hydroxyiminomethyl, lower alkoxyiminomethyl, carbamoyl, carbamoyl-lower alkenyl or carbamoyloxy-lower alkyl, the group .dbd.NOR.sup.

Abstract: Antimicrobial 2-oxo-1-azetidinesulphonic acids of the formula ##STR1## in which H.sub.2 N ##STR2## represents an amino-substituted thiazolyl group, R.sup.1 is lower alkyl which is substituted by carbamoyl, lower alkylsuphonyl, azido, piperidine-carbonyl, (hexahydro-1H-azepin-1-yl)carbonyl or lower alkynyl, and R.sup.2 is hydrogen or a lower organic group, typically, carbamoyloxymethyl.

Abstract: There is presented optically uniform .beta.-lactams of the formulae ##STR1## wherein Z is a readily cleavable acyl group, R.sup.1 is amino or a group convertible into amino, R.sup.2 is hydrogen or a readily cleavable protecting group and R.sup.3 and R.sup.4 each are a lower hydrocarbon group which optionally contains oxygen and which is attached via a carbon atom, whereby these groups can also be joined with one another to form a ring, with the proviso that R.sup.1 is a readily cleavable acylamino when R.sup.2 is hydrogen,and the corresponding optical antipodes, their manufacture and use in the manufacture of antimicrobially-active .beta.-lactams as well as novel intermediates usable in their manufacture.

Abstract: The manufacture of 1-sulpho-2-oxazetidine derivatives of the formula ##STR1## in which Het is an optionally amino-substituted, 5- or 6-membered, aromatic heterocycle containing 1 or 2 nitrogen atoms and optionally also an oxygen or sulphur atom, R.sup.1 is hydrogen, lower alkyl, phenyl-lower alkyl, lower alkanoyl, lower alkoxycarbonyl, lower alkenyl-lower alkyl, lower alkoxycarbonyl-lower alkyl, phenyl-lower-alkoxycarbonyl-lower alkyl, nitrophenyl-lower-alkoxycarbonyl-lower alkyl or carboxy-lower alkyl and R.sup.2 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, lower alkoxycarbonyl, lower alkanoyloxy-lower alkyl, lower alkoxycarbonyl-lower alkenyl, hydroxyiminomethyl, lower alkoxyiminomethyl, carbamoyl, carbamoyl-lower alkenyl or carbamoyloxy-lower alkyl, the group .dbd.NOR.sup.

Abstract: There is presented optically uniform .beta.-lactams of the formulae ##STR1## wherein Z is a readily cleavable acyl group, R.sup.1 is amino or a group convertible into amino, R.sup.2 is hydrogen or a readily cleavable protecting group and R.sup.3 and R.sup.4 each are a lower hydrocarbon group which optionally contains oxygen and which is attached via a carbon atom, whereby these groups can also be joined with one another to form a ring, with the proviso that R.sup.1 is a readily cleavable acylamino when R.sup.2 is hydrogen,and the corresponding optical antipodes, their manufacture and use in the manufacture of antimicrobially-active .beta.-lactams as well as novel intermediates usable in their manufacture.

Abstract: There is presented optically uniform .beta.-lactams of the formulae ##STR1## wherein Z is a readily cleavable acyl group, R.sup.1 is amino or a group convertible into amino, R.sup.2 is hydrogen or a readily cleavable protecting group and R.sup.3 and R.sup.4 each are a lower hydrocarbon group which optionally contains oxygen and which is attached via a carbon atom, whereby these groups can also be joined with one another to form a ring, with the proviso that R.sup.1 is a readily cleavable acylamino when R.sup.2 is hydrogen,and the corresponding optical antipodes, their manufacture and use in the manufacture of antimicrobially-active .beta.-lactams as well as novel intermediates usable in their manufacture.