Anti-Cyclisation Reactions of Enantiomeric 1-(2,3-Dihydroxypropyl)uracil Derivatives

Sa？etak The synthesis and enantiomeric features of 2-hydroxymethyl- -tetrahydro-oxazolo[3,2-c]pyrimidine-5,7-(4H,6H)-diones (V) are. described. The diazomethane methylation of these bicyclic compounds afforded 2-hydroxymethyl-6-methyl-tetrahydro-oxazolo- -[3,2-c]pyrimidine-5,7-(4H,6H)-diones (R)-(XXII) and (S)-(XXII), respectively. For the synthesis of (R)-V and (S)-V the respective 5-bromo-1-(2,3-dihydroxypropyl)uracil (R)-(XVII) and (S)-(XVII) were treated with KCN in DMF. The intermediate (R,S)-6-cyano- -1-(2,3-dihydroxypropyl)uracil (XI) was shown to undergo the anti-cyclisation yielding (R,S)-V if heated in DMSO at 40°c