Pyrimidine Acyclo- C-Nucleosides by Ring Transformations of 2-Formyl-L-arabinal

Abstract

The protected 2-formyl- L-arabinal 2 reacted with thiourea and cyanamide in the presence of sodium hydride to afford via ring transformations the 5-[1 R,2 S-1,2-bis(benzyloxy)-3-hydroxypropyl]-1,2-dihydropyrimidines 3 and 4, respectively. Similarly, treatment of 2 with 3-amino-2 H-1,2,4-triazole yielded 6-[1 R,2 S-1,2-bis(benzyloxy)-3-hydroxypropyl][1,2,4]-triazolo[1,5- a]pyrimidine ( 5).