Synthesis and conformation of 3′-O,4′-C-methyleneribonucleosides, novel bicyclic nucleoside analogues for 2′,5′-linked oligonucleotide modification

Abstract

Novel bicyclic nucleoside analogues 3′-O,4′-C-methyleneribonucleosides 1 are conveniently prepared starting from uridine; the sugar puckering of 1 is found to be nearly in the S-conformation by means of PM3 calculations and ¹ H NMR studies.