Both enantiomers of the title drug (2,6-diethyl-4,8-dimethylglycoluril; 1) were prepared from their complexes with (R)- and (S)-BINOL in 59% ((+)-1) and 43% ((−)-1) yield from its racemate. The absolute configuration of (1R,5R)-(+)-1 was determined by an XRD study of the (R)-(+)-BINOL-(+)-1·H₂O complex.