Abstract: The invention relates to a process for inverting the configuration at the optically active carbon atom (*) in compounds of the formula I ##STR1## in which A denotes a carbocyclic or heterocyclic aromatic radical and R denotes an aliphatic, cycloaliphatic or araliphatic hydrocarbon radical, by formylation, treating the resulting compounds with a strong acid or an acid halide and cleaving the oxazolinium derivatives thus obtained, by acid or alkaline hydrolysis, if appropriate via the stage of the N-formyl compound, and to oxazolinium derivatives of the formula III defined herein and formed as intermediate products.

Abstract: Compounds of general formula ##STR1## wherein one of the groups R.sub.1 and R.sub.3 is a straight-chain or branched oxoalkyl group consisting from 5 to 8 carbon atoms and the oxygen atom is attached to a non-terminal carbon atom and is separated from the nearest ring nitrogen atom by at least 3 carbon atoms in (.omega.-1)-oxoalkyl groups and by at least 4 carbon atoms in oxoalkyl groups in which the oxygen atom is separated from the terminal carbon atom by more than one carbon atom, R.sub.2 and the other one of groups R.sub.1 and R.sub.3 are straight chain or branched alkyl groups containing from 1 to 12 carbon atoms but wherein that group R.sub.1 or R.sub.3 which is other than an oxoalkyl group may also be hydrogen, one nitrogen-bound substituent being hydrogen or alkyl containing more than 1 carbon atom, and physiologically acceptable acid addition salts thereof, a process for their preparation and pharmaceutical compositions containing said compounds.

Abstract: Compound of the formula ##STR1## wherein one of the groups R.sub.1, R.sub.2 and R.sub.3 is a hydroxyalkyl group containing from 4 to 8 carbon atoms, one of the other two, which may be the same or different, is an alkyl group containing from 2 to 12 carbon atoms and the third one is an alkyl group containing from 1 to 12 carbon atoms or a hydrogen atom, R.sub.2 however being an alkyl or hydroxyalkyl group, at least one of the groups R.sub.1, R.sub.2 and R.sub.3 containing at least 5 carbon atoms, a process for their preparation and a pharmaceutical composition containing said compounds.