[The enantioselectivity of drugs]

The syntheses of racemic and enantiometric basically substituted barbiturates, pyrrolidinediones (succinimides) and piperidinediones (glutarimides) are reported. Their absolute configurations are determined. In animal experiments most of the enantiomers show differences in their efficiency. The enantiomers of the barbiturates 4b and 4h and of the pyrrolidinedione 23a possess qualitatively different effects: (S) (-) 4b and (R) (+) 4h are narcotics, (R) (+) 4b and (S) (-)4h are convulsives; (R) (+) 23a is active as an anticonvulsant, (S) (-) 23a is toxic in the doses used.