Abstract: 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 &agr;-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.