one another such that optimal separation capacity is achieved at the highest possible flowrates usually the pressure to be used ranges from 0 3 to 2 0 mpa preferably from 0 5 to 0 7 mpa and the temperature from 20 to 40 u00b0 c preferably 22 to 28 u00b0 c the subject matter of the invention also includes the use of the mirror image isomers of the lactam of formula i synthesized according to the invention for synthesis of active agents having biological activity such transformations are well known to those of ordinary skill in the art of organic synthesis preferably the active agent produced from the enantiomer is a carbocyclic nucleoside analog the present inventive separation method takes place in very robust manner as compared to enzymatic methods the materials used have long shelf lives and the method also permits continuous synthesis of the enantiomers which is extremely advantageous for an industrial process a chromatographic separation of the enantiomers of these substances as described herein has never yet been mentioned in the literature the choice of column material and moving phase from the several thousands of possible combinations makes possible the simple and nevertheless very successful separation of the enantiomers within the scope of the invention the.