SYNTHESIS OF THE OPTICALLY ACTIVE 1,3-DIMETHYLALLANTOINS VIA (-)-MENTHYL ESTERS OF THEIR BICYCLIC TAUTOMERS

Article abstract of DOI:10.1016/S0040-4039(01)80571-2

Availability of both diastereomers of 1-(-)-menthoxy-2,4-dimethyl-3,7-dioxo-2,4,6,8-tetraazabicyclo<3.3.0>octane (5) through decarboxylative rearrangement of 5-(-)-menthoxy-1,3-dimethyl isouric acid (1) allowed the access to both enantiomers of 1,3-dimethylallantoin (6); circular dichroism spectra of the related homologues (-)-6a and (-)-allantoin proved their corresponding R-configurations.