Abstract: The invention relates to novel racemic and optically active trans apovincaminic acid ester derivatives of formula (I), ##STR1## wherein R means hydrogen or a group (a), wherein Z stands for C.sub.1-4 alkyl, optionally substituted aryl, aralkyl, heteroaryl or 14-eburnameninyl group; and n is an integer of 2, 3 or 4, as well as therapeutically acceptable salts thereof. The invention further relates to pharmaceutical compositions containing these compounds as well as a process for the preparation of the above compounds and compositions, and in addition, to a method of treatment. The novel compounds of Formula (I) exhibit particularly antioxidant, antiischemic as well as antiamnesic effects and are useful for inhibiting lipid peroxidation and for protection from or treatment of ischemia and amnesia as well as for treating various degenerative neurological diseases, e.g. Alzheimer's disease.

Abstract: The invention relates to novel 2-oxo-1-oxa-8-azaspiro[4,5]decane derivatives of the formula (I), ##STR1## wherein X means oxygen or an >NR group, whereinR stands for hydrogen; a C.sub.1-12 alkyl; C.sub.3-6 cycloalkyl; carbocyclic C.sub.6-10 aryl or carbocyclic C.sub.6-10 aryl-C.sub.1-4 alkyl group, the two latter two substituents optionally substituted on their aromatic moiety by one or more, same or different halogen, one or more C.sub.1-4 alkyl, C.sub.1-4 alkoxy or trihalomethyl group; or a tosyl group;R.sup.1 and R.sup.2 together represent a methylene group or, when X stands for an >NR group wherein R is as defined above, one of R.sup.1 and R.sup.2 m may represent a hydroxyl group and the other one is a methyl group; andR.sup.3 means hydrogen, benzyl, (C.sub.1-4 alkoxy)carbonyl, phenoxycarbonyl, benzyloxycarbonyl, formyl, piperidin-1-ylcarbonyl, morpholin-4-ylcarbonyl, 4-methylpiperazin-1-ylcarbonyl, 4-(2-hydroxethyl)piperazin-1-ylcarbonyl, 2-chloro-3-nicotinoylcarbamoyl or C.sub.

Abstract: The invention relates to novel, therapeutically active 4-methylene-2-oxo-8-azaspiro[4,5]decane derivatives of the compound, ##STR1## wherein X means oxygen or an >NR group, whereinR stands for hydrogen, C.sub.1-12 alkyl, C.sub.3-6 cycloalkyl, carbocyclic C.sub.6-10 aryl or carbocyclic C.sub.6-10 arylC.sub.1-4 alkyl group, the latter two being optionally substituted on their aromatic moiety by one or more, same or different halogen(s) or one or more C.sub.1-4 alkyl group(s) or by one or more C.sub.1-4 alkoxy group(s);R.sup.3 and R.sup.4, which are the same or different, represent hydrogen, one or more halogen(s), C.sub.1-4 alkyl, C.sub.1-4 alkoxy, trihalomethyl group or hydroxyl group optionally esterified by a C.sub.1-4 alkanoic acid; andis 1 or 2,their isomers, solvates, hydrates, acid addition and quaternary ammonium salts.

Abstract: The invention relates to, therapeutically active 2-oxo-3,8-diazaspiro[4,5]decane derivatives (I), ##STR1## wherein R means hydrogen, a C.sub.1-12 alkyl, C.sub.3-6 cycloalkyl, carbocyclic C.sub.6-10 aryl or carbocyclic C.sub.6-10 aryl-C.sub.1-4 alkyl group, the latter two optionally being substituted on their aromatic moiety by one or more, same or different halogen(s) or one or more C.sub.1-4 alkyl or C.sub.1-4 alkoxy group(s);one of R.sup.1 and R.sup.2 stands for a hydroxyl group whereas the other means a methyl gorup;R.sup.3 and R.sup.4, which are the same or different, represent hydrogen, one or more halogen(s), C.sub.1-4 alkyl, C.sub.1-4 alkoxy, trihalomethyl group or a hydroxyl group optionally esterified by a C.sub.1-4 alkanoic acid; andn is 1 or 2,their isomers, solvates, hydrates, acid addition and quaternary ammonium salts.

Abstract: The invention relates to novel, therapeutically active 4,4-disubstituted piperidine derivatives of the formula (I), ##STR1## wherein R.sup.1 means hydrogen or --CONHR group, whereinR stands for hydrogen, C.sub.1-12 alkyl, C.sub.3-6 cycloalkyl, carbocyclic C.sub.6-10 aryl or carbocyclic C.sub.6-10 aryl-C.sub.1-4 alkyl group, the latter two being optionally substituted on their aromatic moiety by one or more, same or different halogen(s) or one of more C.sub.1-4 alkyl or C.sub.1-4 alkoxy group(s);R.sup.2 stands for an ethynyl or acetyl group;R.sup.3 and R.sup.4, which are the same or different, represent hydrogen, one or more halogen(s), C.sub.1-4 alkyl, C.sub.1-4 alkoxy, trihalomethyl group or hydroxyl group optionally esterified by a C.sub.1-4 alkanoic acid; andn is 1 or 2,as well as their pharmaceutically acceptable acid addition and quaternary ammonium salts.