Abstract: A process for the preparation of 1-substituted azacycloalkan-2-ones of the formula I ##STR1## in which R, m and n have the meanings indicated by reaction of corresponding 1-trimethylsilylazacycloalkan-2-ones with alkali metal alcoholate or alkali metal oxide and then alkylation of the alkali metal salts which are formed.

Abstract: Acylaminopenicillanic acids of the general formula ##STR1## in which A represents phenyl which may be substituted, an aromatic monocyclic heterocycle which may be substituted or dihydrophenyl, and X represents one of the groups --SO.sub.2 --, --CO--, --P(R)-- or --P(O)(R)-- in which R represents low molecular weight alkyl, alkenyl, alkoxy, aralkyl, aralkoxy, aryl or aryloxy which may be substituted, non-toxic salts of these compounds and pharmaceutical compositions containing these compounds.

Abstract: Acylaminopenicillanic acids of the general formula ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 represent hydrogen or lower alkyl which may be substituted, and in which the radicals R.sup.1 and R.sup.2 or R.sup.2 and R.sup.3 may form together an alkylene radical which may be substituted, R.sup.4 and R.sup.5 represent hydrogen or lower alkyl, R.sup.6 represents phenyl which may be substituted, a monocyclic aromatic heterocycle which may be substituted, or dihydrophenyl, A represents a benzene or thiophene ring which may be substituted, and X represents oxygen or a single bond, a process for preparing them and pharmaceutical compositions active against bacterial infections containing these compounds.

Abstract: The present invention relates to a new process for the preparation of 6-aminopenicillanic acid and 7-amino-cephalosporanic acid derivatives by treating the corresponding acylamino derivatives with phosphinic acid chlorides, reacting the mixed acid anhydrides so obtained with agents forming imidohalides, converting the imido halides into iminoethers and hydrolysing them.