Abstract: A chemical process is disclosed for the preparation of a pharmaceutically active compound in stereospecific form selected from the group of compounds having the formula: ##STR1## and their physiologically compatible salts and esters, wherein R is a lower alkyl and Ar a monocyclic, polycyclic or orthocondensed polycyclic aromatic group having up to 12 carbon atoms in the aromatic ring, and which may be substituted or unsubstituted in the aromatic ring, comprising the steps:a) reacting a carbonyl substrate of the formula: ##STR2## where R and Ar have the meanings given above, with a stereospecific reagent in the presence of a reducing agent and an organic solvent to form the enatiomeric carbinol andb) reacting the enantiomeric carbinol obtained to form the end product.

Abstract: A chemical process is disclosed for the preparation of a pharmaceutically active compound in an enantiomeric form either (R) or (S) of the structure ##STR1## and a suitable pharmaceutical salt, e.g. alkali or earth metal, D-glucamine or D-ribamine, where R.sub.1 represents an optionally substituted aryl group same as phenyl or naphthyl group, optionally including a heterocyclic ring system, which is optionally substituted, or represents a hetero-aromatic ring system optionally containing in addition to carbon atoms one or more atoms selected from the group consisting of nitrogen and oxygen; the enantiomeric R or S-compounds of (I) are obtained from a suitable ketone (II) by reduction with an LiAlH.sub.4.sup.