Abstract
(R,S)-5-Ethyl-5-(2′-pentyl)barbituric acid (I)1,2 is metabolized in vivo to give all four possible optical isomers of 5-ethyl-5-(3′-hydroxy-1′-methylbutyl)barbituric acid (II). 3,4 From metabolism studies of pure (1′S)- I and (1′3)-I, Palmer and co-workers4,5 were able to determine the relative amounts of each of the four isomers formed. These studies showed that (1′S)-I gave mainly one enantiomer of (1′S)-II, whereas (1′R)-I gave approximately equal amounts of both (1′R)-II enantiomers.