The invention relates to a process and intermediates for the preparation of enantiomerically pure cycloalkanoindolecarboxylic acids and azaindolecarboxylic acids and pyrimido�1,2a!indolecarboxylic acids and their activated derivatives, characterized in that the tolyl acetic acid is first esterified with a chiral alcohol, then diastereoselective substitution at .alpha.-carbon atoms is carried out and this product is halogenated in the tolyl group and then reacted with appropriate cycloalkanoindoles, cycloalkanoazaindoles or pyrimido�1,2a!indoles. It is possible by this method to prepare specifically, in high purity, the enantiomerically pure carboxylic acids which are intermediates for valuable medicaments.