Process for the preparation of pharmaceutically active thiazolidine or oxazolidine compounds by a yeast reductase

A process for preparing a compound of formula (I), or a tautomeric form thereof and/or a pharmaceutically acceptable salt thereof and/or a pharmaceutically acceptable solvate thereof, wherein: T represents a substituted or unsubstituted aryl group and T is O or S; which process comprises, treating a compound of formula (II), or a tautomeric form thereof and/or a salt thereof and/or a solvate thereof, wherein T and T are as defined in relation to formula (I), with a microbial reductase obtained from an appropriate red yeast; and thereafter, as required, preparing a pharmaceutically acceptable salt and/or a pharmaceutically acceptable solvate of the compound of formula (I) or a tautomeric form thereof; compounds prepared by such a process and the use of such compounds in medicine.