SYNTHESIS OF 4 STEREOISOMERS OF CARBOCYCLIC 5'-NOR D4A AND EVALUATIONOF THEIR TRIPHOSPHATES AS SUBSTRATES FOR DNA-POLYMERASES

A method was developed for synthesis of the four stereoisomeric enanti omerically pure 5'-nor carbocyclic nucleosides 4b, ent-4b, 10 and ent- 10 starting from the common enantiomerically pure allylic monoacetate 1. Nucleoside analogues were converted to the corresponding triphospha te derivatives 6, ent-6, 12, and ent-12. The substrate properties of t he latters towards different DNA polymerases were evaluated.