Reduction of 3-aminoquinoline-2,4(1H,3H)-diones and deamination of the reaction products
3-Aminoquinoline-2,4-diones were stereoselectively reduced with NaBH 4 to give cis-3-amino-3,4-dihydro-4-hydroxyquinolin-2(1H)-ones. Using triphosgene (=bis(trichloromethyl) carbonate), these compounds were converted to 3,3a-dihydrooxazolo[4,5-