Synthesis and properties of oligonucleotides containing carbocyclic L-nucleoside analogues with a restricted glycosyl conformation.

To construct nuclease-resistant oligonucleotides, we designed novel carbocyclic L-nucleoside analogues (1-4) whose glycosyl conformation is fixed at chi = 180 degrees by an oxygen-bridge between the base and the cyclopentane ring. We have already achieved the racemic synthesis of these analogues. In this study, we succeeded in synthesizing an optically active form of these analogues. The properties of oligonucleotides containing them will be shown.